Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
“Aquakosmos”
Colorful chandeliers, passing spirits, sprouting mushrooms, and fountains of falling ink appear in Christopher Dormoy’s “Aquakosmos.” Driven by the slight density difference between ink and water, many of these elaborate shapes result from the Rayleigh-Taylor instability. Anytime you see mushroom-like plumes and chandelier-like splitting vortex rings, there’s probably a Rayleigh-Taylor instability behind it. Check out…
Stopping a Bottle’s Bounce
A few years ago, the Internet was abuzz with water bottle flips. Experimentalists are still looking at how they can arrest a partially fluid-filled container’s bounce, but now they’re rotating the bottles vertically rather than flipping them end-over-end. Their work shows that faster rotating bottles have little to no bounce after impacting a surface. The…
Mitigating Urban Floods
For densely-populated urban areas, floods are one of the most damaging and expensive natural disasters. We can’t control the amount of rain that falls, so engineers need other ways to mitigate damage. It’s not usually possible to remove people and property from floodplains, so instead civil engineers look below the surface, building flood tunnel networks…
Weathering Spilled Oil
As long as we continue to extract and transport oil, marine oil spills will continue to be a problem. Recent work shows that spilled oil weathers differently depending on both sunlight and water temperature. When exposed to sunlight, crude oil undergoes chemical reactions that can change its makeup. Researchers studied the mechanical properties of crude…
Rolling Over Wisconsin
Although they may look sinister, roll clouds like this one are no tornado. These unusual clouds form near advancing cold fronts when downdrafts cause warm, moist air to rise, cool below the dew point, and condense into a cloud. Air in the cloud can circulate around its long horizontal axis, but the clouds won’t transform…
Diving From Above
Blue-footed boobies, like many other seabirds, climb to a particular altitude before folding their wings and diving head-first into the water. This acrobatic feat balances the bird’s force of impact and the depth it can reach to ensnare fish swimming there. It’s an incredible process to watch, a fascinating one to study, and, here, a…
Butterfly Scales
Catch a butterfly, and you’ll notice a dust-like residue left behind on your fingers. These are tiny scales from the butterfly’s wing. Under a microscope, those scales overlap like shingles all over the wing. Their downstream edges tilt upward, leaving narrow gaps between one scale and the next. Experiments show that, although butterflies can fly…
Fishing With Mucus
The scaled wormsnail isn’t much for travel. It lives its whole life cemented to a rock in the tidal lands. And when you can’t go out for food, you have to wait for the food to come to you. During high tides, the snail lets out tendrils of mucus that capture bits of kelp, plankton,…
Drag Is Greatest Before Submersion
A new study shows that partially submerged objects can experience more drag than fully submerged ones. This unexpected result comes from the excess fluid that piles up ahead of the object, as seen in the image above, where flow is moving from left to right. The experiments used centimeter-sized spheres and showed that the maximum…