Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Dissolving
It looks like the fiery edge of a star’s corona, but this photo actually shows a dissolving droplet. The droplet, shown as the lower dark region in this shadowgraph image, is a mixture of pentanol and decanol sitting in a bath of water. Pentanol is a type of alcohol that is fully miscible with decanol…
Turbine Wakes in the Sea
What we we build always has an impact on the environment around us. The white dots you see in the image above are an array of offshore wind turbines, standing in waters 20 to 25 meters deep. The brownish lines extending from each turbine show the underwater wakes of the turbines, colored by the sediment…
A Water Balloon on a Bed of Nails
If you dropped a water balloon on a bed of nails, you’d expect it to burst spectacularly. And you’d be right – some of the time. Under the right conditions, though, you’d see what a high-speed camera caught in the animation above: a pancake-shaped bounce with nary a leak. Physically, this is a scaled-up version…
Pascal’s Barrel
Pascal’s Law tells us that pressure in a fluid depends on the height and density of the fluid. This is something that you’ve experienced firsthand if you’ve ever tried to dive in deep water. The deeper into the water you swim, the greater the pressure you feel, especially in your ears. Go deep enough and…
Geological Flowers
These strange flower-like formations appear in a former limestone quarry in France. The black that you see is bitumen, or asphalt. These dendritic structures appear in spots where the rock has fractured. Originally, two rock faces met here, with a thin layer of bitumen glued between them. As one face pulled away, air began to…
Weather Posters
Weather Underground has created a whole series of posters celebrating and briefly explaining various weather phenomena. Many of their subjects are beautiful and unusual types of clouds like the lenticular clouds that form over mountains and hole-punch clouds created when supercooled water vapor gets disturbed. They have a few non-cloud phenomena we’ve discussed previously, too,…
Washington Ice Disk
Winter weather in northern latitudes sometimes brings with it unusual phenomena like this ice disk spinning in the Middle Fork Snoqualmie River in Washington state. Photographer Kaylyn Messer ventured out to capture photos and videos of the event over the weekend. There are a couple theories as to how such disks form, but swirling river eddies are…
“Pulse”
Photographer Mike Olbinski returns with another incredible storm-chasing timelapse video, this time all in black-and-white. To me, that choice helps “Pulse” emphasize the ominous majesty of these supercells and tornadoes by highlighting the textures that make up the clouds. Watching clouds in timelapse, they seem to materialize from nowhere as moisture drawn up from the…
Shot Through a Drop
Shoot a sphere through a drop with sufficient speed, and you’ll see something like the composite photo above. Going from right to left, the projectile is initially coated in liquid and stretches the fluid behind it as it continues flying. This forms a thin sheet of fluid called a lamella with a thicker, uneven rim…
Crowns On Impact
Dropping a partially-filled test tube of water against a table makes the meniscus at the air-water interface invert into a jet of liquid. In some cases, the impact is strong enough to generate splashing crowns of water around the base of the jet. These crowns come in two forms – one with many splashes layered…