Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Chemical Flowers
These “flowers” blossom as two injected chemicals react in the narrow space between two transparent plates. The chemical reaction produces a darker ring that develops a streaky outer edge due to competition between convection and chemical diffusion. To show how gravity affects the instability, the researchers repeated the experiment on a parabolic flight. In microgravity…
The Delta Series
It’s easy in the rush of our daily lives to forget just how dynamic rivers are. In his “Delta Series” conservation photographer Paul Nicklen explores that ever-changing nature from above the Colorado River delta. With the ongoing megadrought in this region and ever-increasing demands for more water, the Colorado no longer flows to the ocean.…
Turbulence in Accretion Disks
Accretion disks form everywhere, from around young, planet-building stars to massive black holes. As matter circles in the disk, it slowly loses angular momentum and falls inward toward the central gravitational body. But the details of this process have long vexed astronomers. The low-viscosity environment of gas and dust in accretion disks simply is not…
Summer Melt
A warm summer in 2022 has resulted in record melting on Svalbard. Located halfway between the Norwegian mainland and the North Pole, more than half of Svalbard is normally covered in ice. But with glaciers in retreat and firn — a surface layer of compressed porous snow — melting, pale blue ice is getting direct…
Fire Ant Rafts
When you run into a fire ant, you’re in for a bad day. But if you run into a colony-sized raft of fire ants, well, that’s going to be a very bad day. These insects evolved to survive Amazonian floods, and that prowess has helped them spread far from their original homes. When waters start…
A Comet’s Tail Swept Away
On Christmas Day 2021, Comet Leonard put on a show in our skies. Though the comet was a pale streak to the naked eye, photographer Gerald Rhemann caught a striking event: the moment part of the comet’s tail disconnected from its body. The solar wind swept the comet’s gas and dust away. Though I’ve talked…
Aerosols and Instruments
Although COVID has disrupted all of our lives, orchestras saw particular disruption, as little was known about how instruments spread aerosol droplets. In this recent study, a team looked at many wind instruments, as played by professional musicians, for the aerosol load and air flow each instrument creates. They found that, on the whole, wind…
“Keeping Our Sheet Together”
When two liquid jets collide, they form a falling liquid sheet. Here researchers explore how that sheet breaks up when the liquids involved contain polymers. The intact areas of the sheet show as dark red or almost black. The edges of the sheet appear in brighter red and yellow, outlining the holes that form and…
Free Contact Lines
How a simple drop of water sits on a surface is a strangely complicated question. The answer depends on the droplet’s size, its chemistry, the roughness of the surface, and what kind of material it’s sitting on. Vetting the mathematical models that describe these behaviors is especially difficult since droplets often get stuck, or “pinned,”…