Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How Gas Pump Nozzles Work
Ever wonder how a gas pump shuts off when the tank is full? You might guess that there’s a sophisticated electronic sensor hidden in there. But there isn’t! Gas pumps use an entirely mechanical technique to sense a full tank and shut off flow, as Steve Mould demonstrates in this video. There are two key…
Flowers Through a Hazy Veil
A smoke-like haze obscures colorful bouquets in these photographs from artist Robert Peek. To achieve the effect, Peek submerges his subjects underwater with white dye that sinks due to its greater density. The wakes traced by the dye are impressively laminar, so the dye must drift rather slowly past each petal. The overall effect is…
Mixing the Perfect Batter
In baking, there’s a point when wet and dry ingredients get combined to form the batter (or dough) that eventually becomes a tasty treat. Experienced bakers know that the ratio of wet-to-dry must be just right for the final product. Too dry and the mixture won’t come together; too wet and the final product is…
Leaky Resonance
Some resonators aren’t perfect — nor are they meant to be! Here, researchers experiment with resonance using a disk shaking up and down over a pool of water. The disk never touches the water, but its movement makes the air above the water move in and out, like a miniature, changeable wind. The air flow…
Zen Stones
On Lake Baikal, where Siberian winters are long and cold but have little precipitation, you can find a strange phenomenon: stones that balance on a thin spire of ice. Known as Zen stones — thanks to their visual similarity to stacks of balanced stones in Japanese Zen gardens — these natural oddities rely on time…
Dolphins Playing With Bubble Rings
Blow a jet of air underwater and you can make a bubble ring. It takes some practice for humans, or you can use a device. In this video, a team introduced wild dolphins to a bubble-ring-making machine and observed how the dolphins reacted. After some initial wariness, the animals played with them for hours, creating…
Bird Photographer of the Year 2022
Try as we might, humans cannot understand fluid dynamics as birds do. Whether they are primarily flyers or swimmers, birds have an innate understanding of lift and other aerodynamic forces that put the best engineers to shame. Shown here are a subset of winners from the 2022 Bird Photographer of the Year competition, each of…
Anoles Revisited
Longtime readers may recall seeing this little bubble-crowned anole previously. This species dives underwater to escape predators and will breathe and rebreathe a bubble of air for as much as 18 minutes before resurfacing. At the time of my original post, I speculated that the reptile’s hydrophobic skin might provide a large enough bubble surface…
Dune Fields From Space
An astronaut captured this image of the Oyyl Dune Field in Kazakhstan from the International Space Station. To the south and east of the dune field (right and lower parts of image) there are fluvial floodplains, sources of sediment that feed the dunes. With sufficient wind and sand sources, the dune field has grown in…
Dance of the Coral Polyps
Coral reefs are made of up small organisms, called coral polyps, that live together in a colony. Individual polyps can expand, contract, and wave in the flow around them, and, in a recent study, researchers looked at whether changing conditions in temperature and light wavelength can affect polyp movement. To do so, they built a…