Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
A Glimpse of Earth’s Interior
Lava spurts from the Fagradalsfjall volcano in Iceland in this award-winning photo by Riten Dharia. It’s always bizarre to see molten rock flowing in fountains and rivers because it’s so unlike our daily experiences. Some deeply buried areas of the Earth, including the outer part of the core, are often described as liquid rock, which…
Curved Cracks
When mixtures of particles and fluids dry, they typically leave a pattern of straight cracks. Here researchers explore what happens when the drying film contains bacteria from the family E. coli. Instead of straight cracks, the films form curved ones. With bacteria that rotate or tumble, the crack pattern is spiral-like. With bacteria that swim,…
Nacreous Clouds
Iridescent clouds shine bright over this Finnish sunset. These colorful clouds are nacreous clouds, also known as mother-of-pearl clouds. Formed from ice crystals during frigid conditions in the lower stratosphere, these clouds are most visible before dawn and after sunset, when their high altitude catches sunlight while the lower atmosphere doesn’t. These rare clouds form…
Superradiance in Fluids
A group of excited atoms can collectively emit more photons than they could individually in a phenomenon known as superradiance. Now researchers have shown that vibrating fluids can produce superradiance as well. Similar to other hydrodynamic quantum analogs, the researchers vertically vibrated a pool of liquid at a frequency that produced Faraday waves. Beneath the…
Placental Fluid Dynamics
The placenta, critical as it is to human life and development, is likely the least-studied organ in the body. Reasons for that abound, from the ethics of studying pregnant people to the historical marginalization of female bodies in medical studies. But what little we do know shows that the placenta is quite incredible. Shaped somewhat…
Exploding a Bubble
In this high-speed video, artist Linden Gledhill ignites a mixture of oxygen and hydrogen contained within a soap bubble. As neat as the video is, I decided to take a closer look at the initial detonation with this animation: Even here, it’s hard to appreciate just how fast ignition is; it lasts only a handful…
A Game of Toss
Over the past few years, we’ve seen lots of droplets bouncing and walking on waves. But today’s example is a little different. In this set-up, the wave is a large standing wave that sloshes from side-to-side in a narrow container. As it does, the wave catches and tosses a large ~3mm water droplet. The system…
Cellular Clouds
Though tough to make out from the surface, our oceans are often covered by cell-shaped clouds stretching thousands of kilometers. This satellite image shows off two such types of marine stratocumulus cloud. Open-celled clouds appear as thin wisps of vapor around an empty middle; in these clouds, cool air sinks through the center while warm…
Breaking Clots With Sound
Clots that block blood flow away from the brain are one of the most common causes of strokes for younger people. If caught early, anticoagulants can sometimes resolve the issue, but the treatment fails in 20-40% of cases. Now researchers are investigating a new ultrasound technique capable of quickly and effectively removing these clots. The…
Magnetic Soap Films
Soap films naturally thin over time as fluid evaporates and differences in film thickness cause surface-tension-driven flows. In this video, researchers experiment with adding magnetic nanoparticles to the soap film. In the second image, the white structures near the center of the film contain nanoparticles, and they’re drawn toward the magnet that sits (out-of-frame) to…