Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Soapy Rainbows
The swirling psychedelic colors of a soap bubble come from the interference of light rays bouncing off the inner and outer surfaces of the film. As a result, the colors we see are directly related to the thickness of the soap film. Over time, as a film drains, black spots will appear in it. This…
The Many Shapes of Fish
After visiting an aquarium or snorkeling near a reef, you may have wondered why fish come in so many different shapes. Given that all fish species need to get around underwater, why are some fish, like tuna, incredibly streamlined while others, like the box fish, are so, well, boxy? There are several major groupings for…
Waves Below the Surface
Even a seemingly calm ocean can have a lot going on beneath the surface. Many layers of water at different temperatures and salinities make up the ocean. Both of those variables affect density, and one stable orientation for the layers is with lighter layers sitting atop denser ones. Any motion underwater can disturb the interface…
Rainbow Paint on a Speaker
Every year brings faster high-speed cameras and better quality imaging, so the Slow Mo Guys like to occasionally revisit topics they’ve done before, like paint vibrated on a speaker. The physics involved here are fantastic, so I’ll revisit the topic, too! In this version, Gav and Dan are using a pretty beefy speaker at a…
Using Air to Break Up Jets
One method of breaking a liquid into droplets, or atomizing it, uses a slow liquid jet surrounded by an annulus of fast-moving gas. The gas along the outside of the liquid shears it, creating waves that the wind blowing past can amplify. This draws the liquid into thin ligaments that then break into droplets. This…
Sandy Wrinkles
Water flowing back and forth over sand quickly forms a field of dune-like wrinkles. On the upstream side, the flow is a little faster, and it picks up grains of sand. When the flow slows on the downstream side of a bump, the sand gets deposited. In this way, small bumps in the sand continue…
“Water Ballet”
Artist Kamiel Rongen uses common substances like paint, oil, eggs, and even air freshener to create what he calls “water ballet.” His videos are full of ethereal and surreal landscapes full of color and motion. Buoyancy (or the lack thereof) plays a major role in his work – fluids often spurt upward like alien creatures emerging…
Kilauea’s Lava Lake
Hawaii’s Kilauea Volcano continues to erupt, sending magma flowing through multiple fissures. The U.S. Geological Survey has sounded a warning, however, that the volcano could erupt more explosively. Hot spot volcanoes like Hawaii’s generally have more basaltic lava, which has a lower viscosity than more silica-rich magmas like those seen on continental plates. That makes…
Dissolving Candy
In nature, solid surfaces often evolve over time in conjunction with the flows around them. This is how stalactites, canyons, and hoodoos all form and change over time. Here researchers examine a surface formed from hard candy that is dissolving from below. Over time, the initially flat surface develops a pitted appearance (top image, scale…
Mimicking Hurricanes
Hurricanes are a frequent and potentially deadly occurrence for many parts of the world. Although forecasting models have improved, there is still a lot about the physics of these storms that we don’t fully understand, in part because getting direct measurements from the real thing is so difficult and hazardous. Researchers at the University of…