Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Waves Break Up Floating Rafts
Small particles can float on a liquid, held together as a raft through capillary action. But those rafts — like the tea skin below — break up when waves jostle them. In this study, researchers looked at how standing waves broke up a raft of graphite powder. Although the raft’s break-up resembles fields of sea…
Feeding Hurricanes
With the strong hurricane season pummeling the southern U.S. this year, you may have heard comments about how warm oceans are intensifying hurricanes. Let’s take a look at how this works. Above is a map of ocean surface temperatures in late September, as Helene was developing and intensifying. For hurricanes, the critical ocean surface temperature…
“Colors of Glacial Rivers”
As glaciers flow, they grind down rock, creating fine sediment that dyes waterways a milky color. In Jan Erik Waider’s aerial film, we get a bird’s eye view of the result, watching pockets of sediment move downstream in pulsating waves and swirls. Along the coast, ocean waves pass over the internal ones, creating a mesmerizing…
Breaking in Rogue Seas
Many models for forecasting ocean waves simplify the physics by assuming that waves are essentially two-dimensional, like a long breaker heading toward shore. But in the open ocean, waves often come from more than one direction; crossing seas are a good example. When waves from different directions combine, a recent study shows, the resulting wave…
When Fires Make Rain
The intense heat from wildfires fuels updrafts, lifting smoke and vapor into the atmosphere. As the plume rises, water vapor cools and condenses around particles (including ash particles) to form cloud droplets. Eventually, that creates the billowing clouds we see atop the smoke. These pyrocumulus clouds, like this one over California’s Line fire in early…
“Immersion”
Some seabirds, including gannets and boobies, feed by plunge diving. From high in the air, they fold their wings and dive like darts into the water, impacting at speeds around 24 m/s to help them reach the depths where their prey swim. With their narrow beaks and necks, the critical moments in this feat come…
Engineering Our Landfills
We create a lot of waste and, at least for now, much of that waste goes into landfills. Properly managing garbage requires much more than digging a hole in the ground, as Grady from Practical Engineering shows in this video. Maintaining a landfill requires careful management of water, soil, landfill strata, and even gas buildup.…
The Crashing Waves of French Polynesia
Surfer and photographer Tim McKenna lives in the village of Teahupo’o on Tahiti’s southeastern coast. The area’s shallow coral reef system creates some of the world’s biggest barreling waves, which attract surfers from around the world. McKenna captures the majestic power of these surges in these black-and-white photographs; you can find more of his work…
Slushy Snow Affects Antarctic Ice Melt
More than a tenth of Antarctica’s ice projects out over the sea; this ice shelf preserves glacial ice that would otherwise fall into the Southern Ocean and raise global sea levels. But austral summers eat away at the ice, leaving meltwater collected in ponds (visible above in bright blue) and in harder-to-spot slush. Researchers taught…
Swimming With Cilia
Like most microswimmers, these Synura uvella algae use cilia to swim. Cilia are tiny, hair-like appendages that flap to produce thrust. Even under a microscope, the cilia are hard to see because they are so thin and move quickly in and out of the microscope’s narrow focus. A cilia’s stroke is always asymmetric — no…