Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Wave Clouds in the Atacama
Striped clouds appear to converge over a mountaintop in this photo, but that’s an illusion. In reality, these clouds are parallel and periodic; it’s only the camera’s wide-angle lens that makes them appear to converge. Wave clouds like these form when air gets pushed up and over topography, triggering an up-and-down oscillation (known as an…
“Paradolia”
In “Paradolia,” filmmaker Susi Sie plays with pareidolia, our tendency to seek patterns in nebulous data — like faces on a slice of toast. Droplets of miscible and immiscible fluids collide, part, and mix in each sequence, providing plenty of fodder for an active imagination. For myself, my brain especially likes assigning cartoon expressions to…
Inside a Big Cat’s Roar
The roars of big cats — tigers, lions, jaguars, and leopards — carry long distances. In part, this reflects the animals’ size: large lungs exhale lots of air through a large voice-box, whose vibrations resonate in a large throat. But size alone does not make the roar. Below are examples of two big cat voice-boxes.…
A Mini Jupiter
Astronaut Don Pettit posted this image of a Jupiter-like water globe he created on the International Space Station. In microgravity, surface tension reigns as the water’s supreme force, pulling the mixture of water and food coloring into a perfect sphere. It will be interesting to see a video version of this experiment, so that we…
A Magnetic Tsunami Warning
Tsunamis are devastating natural disasters that can strike with little to no warning for coastlines. Often the first sign of major tsunami is a drop in the sea level as water flows out to join the incoming wave. But researchers have now shown that magnetic fields can signal a coming wave, too. Because seawater is…
Skydiving Salamanders
The wandering salamander can spend its entire 20-year lifespan in the canopy of a coast redwood. When predators come calling, they have a special skill that helps them get away: skydiving. These little amphibians have no webbed appendages and no wings, but they’re some of the most skillful skydivers out there. By carefully repositioning its…
Trapped in Ice
On lake bottoms, decaying matter produces methane and other gases that get caught as bubbles when the water freezes. In liquid form, water is excellent at dissolving gases, but they come out of solution when the molecules freeze. In the arctic, these bubbles form wild, layered patterns like these captured by photographer Jan Erik Waider…
Growing Flexible Stalactites
Icicles and stalactites grow little by little, each layer a testament to the object’s history. Here, researchers explore a similar phenomenon, grown from a dripping liquid. They’re called “flexicles” in homage to their natural counterparts, and they start from a thin layer of elastomer liquid. Though it begins as a liquid, elastomer solidifies over time.…
Predicting Droplet Sizes
Squeeze a bottle of cleaning spray, and the nozzle transforms a liquid jet into a spray of droplets. These droplets come in many sizes, and predicting them is difficult because the droplets’ size distribution depends on the details of how their parent liquid broke up. Shown above is a simplified experimental version of this, beginning…
Where to Follow FYFD Online
Hi, folks! As the social media landscape fractured, I’ve been dragging my feet about making some needed changes. But no longer. As of November 2024, I am no longer updating FYFD’s X/Twitter account. Here are the places you can currently follow FYFD online: Most of those services get autoposts rather than regular check-ups, so I…