Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Breaking Ground
Pushing a fluid into a porous granular material can fracture it into branching, lightning-like patterns. Here, air is injected into wet grains as a laboratory analog to hydrocarbon extraction or fracturing to treat contaminated soil. The injection of air compacts grains along the branch boundaries, keeping individual branches separated from one another. The patterns that…
Nestling Droplets
Pay attention after a rainfall, and you may notice beads of water gathering in the corners of a spider’s web or along the leaves of a cypress tree (bottom right). Look closely and you’ll notice that the largest droplets don’t form along a straight fiber. Instead they nestle into the corners of a bent fiber…
What Makes Joints Pop?
Cracking one’s knuckles produces an unmistakable popping noise that satisfies some and disconcerts others. The question of what exactly causes the popping noise has persisted for more than fifty years. It’s generally agreed that separating the two sides of a joint causes low enough pressures to form a cavitation bubble in the sinovial fluid of…
Jupiter’s Belts and Zones
Jupiter’s distinctive bands of colored clouds, known as belts and zones, have been an iconic part of the planet since they were first observed by Galileo. (The scientist, not the space mission!) They are considered part of Jupiter’s weather layer, the region of its atmosphere where storms reign. Thanks to gravitational measurements by the Juno…
Fissures in Africa
Pictures of an enormous fissure in Kenya’s East African Rift Valley have gone viral in recent weeks along with breathless reports about how part of the African continent is splitting away. And while Africa is splitting – very, very slowly – this crack, impressive as it is, may not have anything to do with it.…
How Trees Pull Water
Trees are incredible organisms, and the physics behind them baffled scientists until relatively recently. Inside trees, there is a constant flow of water up from the roots, through the xylem and out the leaves. We often think of atmospheric pressure and capillary action as the mechanisms for pushing water up against the force of gravity,…
Fly Away!
Spiders are often among the first colonists on newly formed volcanic islands. Thanks to their aerial skills, they are able to travel nearly anywhere by ballooning on strands of their own silk. Exactly how spiders as large as 20 milligrams manage this is still relatively known. A new study shows that crab spiders, like any…
Surfaces That Scrape Off Ice
Ice can be a terrible pest, freezing to surfaces like roads and airplane wings and causing all sorts of havoc. Some surfaces, though, can actually prompt a freezing drop to scrape itself off. There are a couple key effects in play here. The first is that the surface is nanotextured – in other words, it…
Dune Networks
In sandy deserts, winds can build a vast network of dunes whose shapes depend on the winds that built them. This photograph, taken by an astronaut aboard the International Space Station, shows part of a Saharan dune field known as the Grand Erg Oriental. Of the five basic types of sand dunes, this field features…
Bouncing, Floating, and Jetting
Get inside some of the latest fluid dynamics research with the newest FYFD/JFM video. Here researchers discuss oil jets from citrus fruits, balls that can bounce off water, and self-propelled levitating plates. This is our third entry in an ongoing series featuring interviews from researchers at the 2017 APS DFD conference. Missed one of the…