Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
What Limits a Siphon
Siphons are a bit mind-boggling for anyone who has internalized the idea that water always flows downhill. But gravity actually allows a siphon’s water to flow up and over an obstacle, provided certain conditions are met. Steve Mould digs into the details of those conditions in this video, where he searches for the maximum height…
“Re:Birth”
In “Re:Birth,” videographer Vadim Sherbakov explores the fascinating patterns of ferrofluids, which suspend tiny ferrous particles in another liquid, often oil. When this magnetic liquid is mixed with ink or paint, its black lines take on a labyrinthine appearance. The result is rather psychedelic, especially with Sherbakov’s bold colors. (Video and image credit: V. Sherbakov)
Ice Discs Surf on Herringbones
Inspired by the roaming rocks of Death Valley, researchers went looking for ways to make ice discs self-propel. Leidenfrost droplets can self-propel on herringbone-etched surfaces, so the team used them here, as well. On hydrophilic herringbones, they found that meltwater from the ice disc would fill the channels and drag the ice along with it.…
Albuquerque: Balloonist Paradise
Albuquerque, New Mexico’s unique weather characteristics make it a popular destination for hot-air balloonists. While balloonists can control their altitude by warming or venting the air in their balloon, their horizontal travel comes at the mercy of the wind. (Just ask the erstwhile Wizard of Oz.) What makes Albuquerque special is a combination of topography,…
Flipping Icebergs
When an iceberg flips, it creates waves that can endanger ships nearby, but the move can also trigger further melting. In the ocean, many factors, including wind and waves, can contribute to an iceberg flipping, so researchers studied small, lab-scale versions to see how melting–alone–affects an iceberg’s likelihood of flipping. The results showed that melting…
Spinning Water
If you spin a tank of water at a constant speed, it takes on a curved, parabolic shape–a demonstration often called Newton’s bucket. Here, a team from UCLA shows how it’s done, both in terms of the equipment needed and a concise explanation of the physics. In the rotating experiment, water is subjected to both…
“Veins of Light and Rivers of Fog”
Tendrils of fog flow over the crest of a hill in this award-winning photograph from Ray Cao. Seen in timelapse, scenes like this show the sloshing, wave-like motion of fog. They’re a beautiful reminder that air and water move much the same. (Image credit: R. Cao/IAPOTY; via Colossal)
Striations on the Sun
One of the perpetual challenges for fluid dynamicists is the large range of scales we often have to consider. For something like a cloud, that means tracking not only the kilometer-size scale of the cloud, but the large eddies that are about 100 meters across and smaller ones all the way down to the scale…
Dispersing Pollutants via Smokestack
In our industrialized society, pollutants are, to an extent, unavoidable. Even with technologies to drastically reduce the amount of pollutants leaving a factory or plant, some will still get released. It’s up to engineers to make sure that those released spread out enough that their overall concentration does not pose a risk to public health.…
Dusty Clouds Make More Ice
Even when colder than its freezing point, water droplets have trouble freezing–unless there’s an impurity like dust that they can cling to. It’s been long understood in the lab that adding dust allows water to freeze at warmer temperatures, but proving that at atmospheric scales has been harder. But a new analysis of decades’ worth…