Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Actinoform Clouds
Flower-shaped actinoform clouds, like those seen on the left side of this satellite image, were only discovered in the 1960s once satellite imagery allowed meteorologists to identify cloud structures that were too large to recognize from the ground. Often appearing over the ocean, these clouds can stretch over hundreds of kilometers, bringing drizzling rain. This…
“Timedrift II”
As a teenager, I climbed Mount Kilimanjaro. The final ascent began around midnight, and we climbed through the dark, through sunrise, and into the early morning. I remember pausing at one point, just as the sun was rising, and looking out at the clouds thousands of meters below. From that height, they looked like an…
Rotating Waves of Grains
Rotating drums are a popular way to explore granular dynamics. Here, researchers fill a cylinder (seen below) with heavy grains and a low-viscosity fluid, then rotate the mixture about a horizontal axis. This sets up a contest between centrifugal forces and gravitational forces on the grains. At the right rotation rates, the grains form annular…
Inside a Metal Vortex
What do you get when you combine liquid gallium, a blender, and a special probe lens? Some pretty wild slow-mo video of a liquid metal vortex, courtesy of the Slow Mo Guys. This video is almost as notable for its set-up as it is for the high-speed footage, given the lengths Gav and Dan go…
Neptune’s Seasonal Changes
Ice giant Neptune orbits our sun once every 165 years, meaning that each season on the planet lasts about 41 years here on Earth. Currently, the side of Neptune facing us is entering early summer, but a recent survey of atmospheric measurements show that Neptune’s stratosphere is experiencing some unexpected changes. Between 2003 and 2018,…
Escaping the Flood
Fire ants clump together into giant rafts to stay alive during floods. But these rafts won’t form with just any number of ants. Researchers found that individual ants will actually kick one another away. It’s not until there are about ten ants that the raft formation becomes stable. In this video, the team lays out…
“Metamorphe”
A smoke-like haze drifts over surreal landscapes in the “Metamorphe” series by Reuben Wu and Jenni Pasanen. Though fluidic in appearance, these pieces are a merger between Wu’s drone light photography and Pasanen’s AI-assisted digital creations. Even so, the images are extremely evocative of fluid motion, connected as they are to human senses (like smell,…
Swimming Together
Scientists have long pondered the possibilities of hydrodynamic benefits to the ways fish school. But most analyses of schooling have assumed a fixed spacing that’s far more orderly than what we observe in nature. In this experiment, researchers instead used a pair of robotic swimmers (essentially hydrofoils) to explore a range of swimming formations. What…
How Dunes Form
On its face, the idea that sand and wind can come together to form massive mountainous dunes seems bizarre. But dunes — and their smaller cousins, ripples — are everywhere, not just on Earth but on other planetary bodies where fine particles and atmospheres interact. In this video, Joe Hanson gives a great overview of…
You’re Drunk, Toadlet
Most frogs and toads are excellent jumpers, taking off and landing with a control and grace that rivals elite athletes. Not so for the pumpkin toadlet. These species have become so miniaturized that the structures of their inner ears are too narrow for the fluid flow that helps frogs (and humans!) orient themselves in space.…