Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Mediterranean Currents
Ocean currents play a major role in the weather and climate of our planet. This video shows a simulation of the surface ocean currents in the Mediterranean and Atlantic over an 11-month period. Each second corresponds to 2.75 days. You’ll see many swirling eddies in the Mediterranean and more flow along the coastlines in the…
Bubbles and Films Merging
As we’ve seen before, a water droplet can merge gradually with a pool through a coalescence cascade. It turns out that the coalescence of a soap bubble with a soap film can follow a similar process! Initially, the bubble and film are separated by a thin layer of air. Once that air drains away and…
A New Cloud
These unusual and spectacular clouds are known as undulatus asperatus. Though they have been proposed as a new type of cloud, they are as yet officially unrecognized. Despite their dramatic appearance, these clouds are not associated with storms. Instead, they’re thought to form in a process similar to mammatus clouds, where wind shear at the…
Coastal Upwelling
Cool temperatures and abundant nutrients make the waters off the western coast of North America especially biologically productive. This image is a composite of satellite data highlighting large phytoplankton blooms in the California Current. This current runs southward along the coastline, and, like other eastern boundary currents, it experiences strong upwelling, or rising of colder,…
Crown Splash Sealing
A sphere falling into water generates a spectacular crown splash at the surface. The object’s impact ejects a thin sheet of fluid that rises vertically. The air pulled down into the cavity by the sphere’s passage makes the air pressure inside the sheet lower than the ambient air pressure on the exterior of the sheet.…
Auroras From Space
NASA has released a jaw-dropping new compilation of Earth’s auroras viewed from the International Space Station. It’s available in up to 4K resolution, and I heartily recommend watching it fullscreen at the highest resolution you can comfortably manage. (To paraphrase: this is ultra high definition – it’s better resolution than real life!) I don’t think…
Pinning a Drop
The shape of a droplet sitting on a surface depends, in part, on its surface tension properties but also on the nanoscale roughness of the surface. Small variations in the height and shape of the surface will change the area a drop contacts as well as the contact angle the edge of the drop makes…
Shock Waves in Flight
This week NASA released two new images of the shock waves surrounding T-38C jets in free flight. They’re the result of NASA’s new adaptations of the schlieren photography technique, which has let scientists visualize shock waves (in the lab, at least) for more than a century. To celebrate, I thought it would be fun to…
Fluids Round-up
Time for another look at some of the best fluids content out there. It’s the fluids round-up – with a special focus this week on oceans! – Ryan Pernofski spent two years filming the ocean in slow motion with his iPhone to make the short film “Slowmocean” seen above. It’s a gorgeous ode to the beauty…
The Brazil Nut Effect
The Brazil nut effect is a common name for the phenomenon where large particles tend to rise to the top of a mixture when it’s shaken. It’s also the subject of the latest FYFD video, which you can see above. I’ve seen other mentions of the topic previously, but when I started researching the literature,…