Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
A Braided River
The Yarlung Zangbo River winds through Tibet as the world’s highest-altitude major river. Parts of it cut through a canyon deeper than 6,000 meters (three times the depth of the Grand Canyon). And other parts, like this section, are braided, with waterways that shift rapidly from season to season. The swift changes in a braided…
Smoke Bomb
With a flurry of motion along its pectoral fin, a sting ray lifts the sand nearby and disappears into the turbid cloud. This tactic helps the animal both hide and escape. In a similar move, sting rays and other bottom-dwelling fish can bury themselves in sand.(Image credit: Y. Coll/OPOTY; via Colossal)
Biodegradable PIV Particles
Particle image velocimetry–PIV, for short–is used to visualize fluid flows. The technique introduces small, neutrally-buoyant particles into the flow and illuminates them with laser light. By comparing images of the illuminated particles, computer algorithms can work out the velocity (and other variables) of a flow. Typical methods use hollow glass spheres or polystyrene beads as…
Seeking Randomness
Securing information on the Internet requires a lot of random numbers, something computers are not good at creating on their own. This need for random input raises an important philosophical and practical question: what is randomness? How can we be sure that something truly is random, or is it enough for a system to be…
Compressing Jupiter’s Magnetosphere
Shaped by its strong internal magnetic field and the incoming solar wind, Jupiter has the largest magnetosphere in the solar system. It also has highly active aurorae at its poles, though they are most visible in ultraviolet wavelengths. A new analysis of Juno’s data shows that on 6-7 December 2022, Jupiter’s magnetosphere got compressed, coinciding…
Rip Currents and Hurricanes
When it comes to the beach, looks can be deceiving. That calm-looking water to the side of big crashing waves may actually be a rip current that carries water back out to the ocean. Rip currents are a result of conservation of mass; just as waves carry water to the shore, something has to carry…
Falling From the Sky
Artist Sho Shibuya paints daily meditations on a copy of The New York Times. These particular examples are part of a recent collection, Falling From the Sky, that features realistic trompe l’oeil droplets that celebrate rain and rainy days. Having spent many an hour contemplating water droplets on my window, I love these. (Image credits:…
Aboard a Hurricane Hunter
For decades, NOAA has relied on two WP-3D Orion aircraft–nicknamed Kermit and Miss Piggy–to carry crews into the heart of hurricanes, collecting data all the while. Every ride aboard a Hurricane Hunter is a bumpy one, but some flights are notorious for the level of turbulence they see. In a recent analysis, researchers used flight…
Cooling Tower Demolition
As part of the demolition of a decommissioned coal-fired power plant in Nottinghamshire, workers simultaneously demolished eight cooling towers. The video is here. As the towers collapse, smoke and dust gets blown both out of the base and up each tower. The flow details are fascinating. The plumes have rings in them, perhaps related to…
Tides Widen Ice Cracks
When icebergs calve off of Arctic and Antarctic coastlines, it affects glacial flows upstream as well as local mixing between fresh- and seawater. A recent study points to ocean tides as a major factor in widening the ice cracks that lead to calving. The team built a simplified mathematical model of an ice shelf, taking…