Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Dandelion Seeds
Each seed on the head of a dandelion has a preferred wind direction, according to new research. Seeds facing the breeze are most likely to release from the head, with those facing other directions holding on tens to hundreds of times harder — until their breeze comes along. To measure the force needed to pluck…
Turning the Beach Pink
Lab experiments and numerical simulations can only take us so far; sometimes there’s no substitute for getting out into the field. That’s why a beach in San Diego turned pink this January and February, as researchers released a safe, non-toxic dye into an estuary. The goal is to understand how small freshwater sources mix with…
The Optical Atom
Researchers applied a quantum mechanical technique to study an evaporating drop in extreme detail. The team trapped a spherical water drop and collected the light scattered off it as it evaporated. Using an analytic technique originally developed for an atom, they were able to study changes in the drop down to the nanometric level without…
Racing Dunes
The deserts of Namibia are home to some of the fastest and most consistent winds in the world. As a result, they’re also home to some of the fastest-moving dunes on Earth. Dunes are shaped and moved by the wind, which pushes sand up the dune’s windward side and dumps it down the leeward side.…
“Dark Matter”
In “Dark Matter” photographer Alberto Seveso captures billowing black pigment against a bright red backdrop. Seveso excels at capturing the developing turbulence in sinking fluids. I’m always blown away by the texture in his images; it almost makes the fluid look fabric-like and solid. Look closely in some of these images and you can catch…
Martian Wind Power
To support a crew on Mars, a landing site must offer resources like water and allow for sufficient power generation. Thus far, most analyses of this sort have focused on the possibilities of solar power, which is limited by day-and-night cycles and seasonal variations, and nuclear power, which carries some risk to the human crew.…
Frozen in Ice
Air can dissolve in water, but not in ice. So as water freezes, any dissolved gases have to get squeezed out in order for the ice crystals to grow. Once the concentration of gases is high enough, a bubble nucleates and gets captured by the growing ice around it. The shape of the final bubble…
Swimming Intermittently
Many fish do not swim continuously; instead, they use an intermittent motion, swimming in a sudden burst and then coasting. This intermittent swimming is tough to simulate, due to its unsteady nature, but a new study does so using some clever computational techniques. Researchers suspected that the energy intensity of a fish’s burst could be…
Beneath the Cavity
When a drop falls into a pool of liquid, it creates a distinctive cavity, followed by a jet. From above the surface, this process is well-studied. But this poster offers us a glimpse of what goes on beneath the surface, using particle image velocimetry. This technique follows the paths of tiny particles in the fluid…
“Elements”
Photographer Mikko Lagerstedt specializes in Nordic landscapes, like the windswept snow seen here. I love the way he’s captured the snow that gets picked up and blown by the wind. Notice the hazy layer of snow hovering over the foreground. This snow is saltating, just as sand does in the desert. When flakes get picked…