Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Painting on Water With Ebru
Ebru is the South West Asian art of painting atop water, similar to suminagashi in Japan or paper marbling in European culture. This video takes you inside the studio of Garip Ay, a Turkish ebru artist, letting you observe some of the tools and techniques he uses. Ay’s painting are incredibly dynamic, transforming from one…
Digging Droplets
A droplet on a surface much hotter than its boiling point will skate on a layer of its own vapor, thanks to the Leidenfrost effect. But if that surface is, instead, a granular mixture like this glass powder, the droplet will dig itself a hole. As in the usual Leidenfrost situation, the heat of the…
Flexible Filament Reduces Drag
Most shapes aren’t streamlined for fluid flow. We call these bulky, often boxy shapes, bluff bodies. Above, we see two examples of a bluff body, a flat plate, in a soap film. On the left, the plate sits perpendicular to the soap film’s top-to-bottom flow. Two large, counter-rotating vortices form behind the plate and a…
Ventilation and Respiratory Disease
In 1977, one passenger with the flu infected 38 people onboard a flight with malfunctioning ventilation. In this video, Dianna digs into the physics of respiratory disease transmission and just why ventilation is so key to preventing it. There are three primary modes of transmission for respiratory diseases like influence or SARS-CoV-2: 1) touching an…
Sundews Weaponize Viscoelasticity
In nutrient-poor soils, carnivorous plants like the cape sundew supplement their diets by eating insects. To entice their prey, the cape sundew secretes droplets of sugary water. But unwary insects who land to feed soon find themselves unable to pull away from this viscoelastic liquid. Complex molecules in the fluid grant it elasticity, so when…
Ferrofluid Snakes
We’re used to seeing ferrofluids — with their suspended iron nanoparticles — as spiky fluids when exposed to a magnetic field. But this is not always the case. Here, the ferrofluid is immersed in a thin liquid layer — window cleaner, in this case — and when a magnet is brought near, it forms snake-like,…
Ultrasound in Medicine
When you hear the term “ultrasound,” your brain likely jumps to grainy black and white images of unborn babies, but this technology has a lot more medical uses than just that! Ultrasound is used to image many parts of the body — earlier this year, I got to see my own heart in action through…
Branching Gels
If you sandwich a viscous fluid between two plates, then pull the plates apart, you’ll often get a complex branching pattern that forms as air pushes its way into the fluid. But the exact results depend strongly on what kind of viscous fluid you used. A new study looks specifically at what happens when that…
Event: Machine Learning in Mechanics
This Thursday, August 27th, the U.S. National Committee on Theoretical and Applied Mechanics is holding a special free webinar series on Machine Learning in Mechanics. Details for each talk and a link to register are available here. Note that the event is free but registration is necessary if you want to receive the Zoom link.…
Speeding Sedimentation
Did you know that particles settle faster in an inclined container instead of a vertical one? This sedimentation phenomenon is known as the Boycott effect, after the researcher who first described it. Boycott noticed that red blood cells settled out of samples faster when the test tubes were inclined. The inclined walls give particles a…