Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Acidic Aerosols
As ocean waves crash, they generate aerosols — tiny liquid and solid particulates — that interact with the atmosphere. Curious about the chemistry of these tiny drops, researchers set out to measure their acidity. That’s easier said than done. Over time, aerosol droplets acidify as they interact with acidic gases in the atmosphere and capturing…
Self-Stopping Leaks
A leak can actually stop itself, as shown in this video. To demonstrate, the team used a tube pierced with a small hole. When filled, water initially shoots out the hole in a jet. The pressure driving the jet comes from the weight of the fluid sitting above the hole. As the water level drops,…
“Volcano Pilot”
Today’s video is something a little different. Rather than looking at fluids and their physics directly, we’ll take a step back and think about how people relate to the subject. This short film, “Volcano Pilot,” follows Haraldur Unason Diego as he reflects on his life’s work. It’s a beautiful and moving glimpse of the life…
Dripping Impact
How does water drip, drip, dripping onto stones erode a crater? Water is so much more deformable that it seems impossible for it to wear harder materials away, even over thousands of impacts. To investigate this, a team of researchers developed a new measurement technique: high-speed stress microscopy. In the process, they found that water…
Inside Viscous Fingers
Sandwich a viscous fluid between two transparent plates and then inject a second, less viscous fluid. This is the classic set-up for the Saffman-Taylor instability, a well-studied flow in which the interface between the two fluids forms a wavy edge that develops into fingers. Despite its long history, though, there is still more to learn,…
Coalescence Symmetry
When droplets coalesce, they perform a wiggly dance, gyrating as the capillary waves on their surface interfere. When the droplets have matching surface tensions, like the two water droplets in the animation on the lower left, the coalescence dance is symmetric. But for differing droplets, like the water and ethanol droplets merging on the lower…
Blowing Up Euler
The mathematics of fluid dynamics still have many unknowns, which makes them an attractive playground for mathematicians of all stripes. One perennial area of interest is the Euler equations, which describe an ideal (i.e., zero viscosity), incompressible fluid. Mathematicians suspect that these equations may produce impossible answers — vortices with infinite velocities, for example —…
Martian Flyover
Fly over a Martian crater in this incredibly detailed 8K video built from Mars Reconnaissance Orbiter imagery. Like Earth’s deserts, Mars is largely shaped by wind, and we get some fantastic views of sand ripples in this flyover. For reference, the vertical scale covered in the video image is roughly 1 kilometer. It’s pretty astounding…
Featherwings in Flight
The featherwing beetle is tiny, less than half a millimeter in length. At that scale, flying is a challenge, with air’s viscosity dominating the forces the insect must overcome. The featherwing beetle, as its name suggests, has feather-like wings rather than the membranes larger beetles use. But a new study shows that these odd wings…
Turquoise Eddies
During the summer months, the Barents Sea between Norway and Russia is streaked with blue and teal swirls. These beautiful patterns are the result of a phytoplankton bloom, as viewed by earth-observing satellites (with a little color enhancement). Although each cell in the bloom is only nanometers across, their collective presence is visible from space!…