Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
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…
Crystalline Critters
In 5th grade, I grew crystals by evaporating solutions of salt water from miniature pie tins. The results were white, boxy crystals whose size depended on how much salt I’d managed to dissolve into the water. But it turns out I could have gotten much cooler results if I’d evaporated my salt water a drop…
Slow Mo Espresso
High-speed photography gives us an alternate glimpse of reality. Here it provides an all-new perspective on making espresso. Surface tension plays a starring role, first in pulling together the film that forms over the exit, then in creating the drips and drops that follow. The break-up of espresso into individual droplets is an example of…
Fungal Fluid Dynamics
Many plants gain the soil-bound nutrients they need by trading with symbiotic fungi. Underground, these fungi spread networks that gather and store phosphorus, which they then trade with host plants to get the carbon they need. Research shows that the fungi can be shrewd traders, moving phosphorus from nutrient-rich areas to poorer ones in order…
Sediment and Coral
As rivers wash sediment toward the sea, they carve elaborate deltas like that of the Rio Cauto in Cuba. Over time these sediments build up marshes, swamps, lagoons, and other wetlands that provide critical habitat and flood control. Sediment also washes into the bay, where it interacts with the coral reefs (light green lines on…
Molten Thermite
This glowing, molten liquid captured by the Slow Mo Guys is thermite. The chemical reaction behind thermite is highly exothermic, hence its intense glow. There’s some great fluid dynamics hiding in this video. First, there’s the dripping thermite (Image 1), which breaks up into droplets via the Plateau-Rayleigh instability before shattering when it hits the…