Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How Mantas Filter But Never Clog
Manta rays spend much of their time leisurely cruising through the water with their meter-wide mouths open. As they swim, they filter plankton, which makes up most of their diet, from the water. And they do so without ever clogging. The inside of the manta’s mouth is lined with gill rakers (upper right), a series…
Water Bottle Flipping Physics
In 2016, a senior talent show launched a new viral craze: water bottle flipping. As improbable as it seems at first glance, physics is actually on your side when it comes to pulling this trick off. As explained in this classroom-oriented paper and the video abstract below, the sloshing of the water in the bottle…
Bioinspiration, Underwater Sniffing, and Mixing Toothpaste
In this month’s FYFD/JFM video, we explore some intersections between the animal kingdom and our own lives. Learn about designing better buildings with inspiration from termites; see the fascinating superpower of the star-nosed mole; and learn what goes into products like the toothpaste you (hopefully) use daily. All this and more in the latest video!…
Exploding Meteors
During the recent Perseid shower, photographer Petr Horálek caught an awesome timelapse of an exploding meteor and the vortex ring it created. This is a type of persistent train left when meteors pass through the upper atmosphere. The exact physics are not well understood because such events are difficult to observe; catching them at all is basically…
Levitating with Sound
Sound can manipulate fluids in fascinating ways, from levitation to vibration. Here researchers use sound to levitate and manipulate droplets and turn them into bubbles. Increasing the acoustic pressure on the levitating droplet flattens it, then slowly causes the drop to buckle. When the buckled film encloses a critical volume, the sound waves resonate inside…
“Hydrophytes”
In “Hydrophytes,” industrial designer Nicole Hone imagines a future in which we’ve designed aquatic plants to counter some of the effects of climate change. To create her plants, Hone designed them with digital tools, then printed them with multi-material 3D printers. Their movements are brought to life with pneumatic pumps that fill and collapse them in…
Flying Beetles, Stinging Nettles, and Jellyfish
In the latest JFM/FYFD video, we tackle some of the less pleasant aspects of summer weather: stopping invasive insects, understanding how plants dispense poison, and looking at the physics behind jellyfish stings. And if you’ve missed any of our previous videos, we’ve got you covered. (Image and video credit: T. Crawford and N. Sharp)
Replacing Kalliroscope
Although you may not recognize the name, you’ve probably seen Kalliroscope (top image), a pearlescent fluid that creates beautiful flow patterns when swirled. This rheoscopic fluid was invented in the mid-1960s by artist Paul Matisse and, over the following decades, became a staple of flow visualization techniques. Kalliroscope contained a suspension of crystalline guanine. Since the…
Flowing Flowers
Granular mixtures with particles of different sizes will often segregate themselves when flowing. In this half-filled rotating drum large red particles and smaller white ones create a stable petal-like pattern. As the drum turns, an avalanche of small particles flows down, forming each white petal. When the avalanche hits the drum wall, a second wave…
Using Sound to Print
Inkjet printing and other methods for directing and depositing tiny droplets rely on the force of gravity to overcome the internal forces that hold a liquid together. But that requires using a liquid with finely tuned surface tension and viscosity properties. If your fluid is too viscous, gravity simply cannot provide consistent, small droplets. So…