Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Coffee, Magnified
Sometimes it’s nice to see a new perspective on something familiar. These images show oils from coffee beans suspended in hot water, as seen under 40x magnification. The crystals you see are caffeine and the variety of shapes in the oil blobs is due to being sandwiched between two layers of glass. You can check…
A Colorful Portrait of Flow
This gorgeous, natural-color image shows Lake Balkhash in southeastern Kazakhstan. In early March, the ice on the lake was beginning to break up, revealing glimpses of swirling sediment below the water’s surface. In contrast, the smaller lakes and ponds of the surrounding area remained frozen amidst the wintery browns of the nearby desert and wetlands.…
Vortex Rings on V-Shaped Walls
Vortex ring impacts are eternally fascinating. Here, researchers explore what happens when a vortex ring encounters a V-shaped wall. Because the outer portions of the vortex ring hit the wall sooner than the inner ones, distortions begin there first. The vortex’s approach creates a pressure gradient that causes flow near the wall to separate, generating…
Self-Started Siphoning
Here’s a fun activity you can do while you #StayHome: build a self-starting siphon. Michael from VSauce explains how in this video. Moving fluids from one location to another is almost always about pressure, and a siphon is no different. To get the water to flow, there must be unequal pressures driving the liquid to…
Lava Barriers
Inspired by protecting people and property from lava flows, researchers investigated how viscous fluids flow downhill past large obstacles. As seen above, when the obstacle is tall enough that the flow does not overtop it, there’s substantial deflection of the fluid both up- and downstream. Upstream of the barrier, the flow gets deeper, and downstream…
The Great Haboob Chase
Few sights look as apocalyptic as the leading edge of an incoming dust storm. Known as a haboob, these storms form when a downdraft spreads along the ground, picking up loose dust as the storm front advances. Winds inside the haboob can be severe; when one swept through Denver last year, my first clue was…
Stratospheric Effects of Wildfires
Australia’s bushfires from earlier this year are offering new insights into how pyrocumulonimbus clouds can affect our stratosphere. A massive, uncontrolled blaze between December 29th and January 4th generated a towering, turbulent cloud of smoke like the one shown above. Using meteorological data, a new study shows this enormous cloud initially rose to 16 km…
Hummingbird Flight in Slow Motion
Hummingbirds are impressive, acrobatic flyers. Their figure-8 wing stroke pattern produces about 70% of their lift on the downstroke, and the remainder during the backward upstroke. But their tails and body motions also play an important role in stabilizing them, especially in gusty winds. They also have some impressive feeding dynamics. Altogether, they’re one of…
Recession at Taku Glacier
A glacier’s snowline marks the location where the amount of summer melting and accumulated snowmass are equal. If, over the course of a season, a glacier experiences more snowfall than melting, its snowline will advance. If melting outweighs accumulation, then the snowline will retreat to higher altitudes. Tracking the snowline gives scientists important data about how the…
Simulating Better Breaking Waves
In the ocean, breaking waves trap air into bubbles that then cluster into foam, but conventional simulations don’t capture this foaminess. For bubbles to cluster into foam, there has to be a force preventing — or at least delaying — their coalescence. Typically, this is caused by impurities in the water that help lower the…