Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How CO2 Gets Into the Ocean
Our oceans absorb large amounts of atmospheric carbon dioxide. Liquid water is quite good at dissolving carbon dioxide gas, which is why we have seltzer, beer, sodas, and other carbonated drinks. The larger the surface area between the atmosphere and the ocean, the more quickly carbon dioxide gets dissolved. So breaking waves — which trap…
Flushing the Brain During Sleep
When we sleep, our brains flush out waste that builds up during our waking hours, but how this happens has been something of a mystery. A new study of sleeping mice has visualized and tracked the flow for the first time. The researchers found that, during a specific sleep phase (the non-rapid eye movement portion),…
A Pitcher Plant’s Rain-Triggered Trap
Pitcher plants all use slippery rims and sticky digestive juices to capture and trap their insect prey. But two species of pitcher plant independently evolved an extra trap: a rain-activated springboard lid. Both the Seychelles pitcher plant and the slender pitcher plant — separated geographically by 6000 kilometers — have a springy, near-horizontal “lid” that…
“Waterfall Wonder”
The Semeru volcano rises in the background of this photo of Java’s Tumpak Sewa waterfall by Joan de la Malla. Rain that falls on the volcano slides down its flank and wanders through the jungle on its way to the spectacular 120-meter-high waterfall. From the clouds wreathing the mountain through the jungle’s drifting fogs to…
Peering Inside a Hailstone
In spring and summer, major thunderstorms can include dangerous and destructive hailstones. In Catalonia, a group of scientists collected hailstones after a record-breaking 2022 storm, finding some as large as 12 centimeters across. Using a dentist’s CT scanner, they looked at the interior of the hailstones, uncovering layers that reveal how the hail grew. In…
Instabilities in Competition
When two liquid jets collide, they form a thin liquid sheet with a thicker rim. That rim breaks into threads and then droplets, forming a well-known fishbone pattern as the Plateau-Rayleigh instability breaks up the flow. This poster shows a twist on that set-up: here, the two colliding jets vary slightly in their velocities. That…
Flow Behind Viscous Fingers
Nature is full of branching patterns: trees, lighting, rivers, and more. In fluid dynamics, our prototypical branching pattern is the Saffman-Taylor instability, created when a less viscous fluid is injected into a more viscous one in an confined space. Most attention in this problem has gone to the branching interface where the two fluids meet,…
Mapping the Oceans With Seals
Elephant seals are harbingers — canaries in the coal mine — for climate change. A long-running experiment tracks northern elephant seal populations using a combination of sensor tags and field measurements. With the miniaturization of sensors, a tagged seal can provide a wealth of data for scientists: foraging paths, temperature and salinity data, behavioral patterns,…
Bubbling Up
By volume, Lake Baikal is the world’s largest lake, holding over 20% of the planet’s fresh water. It’s also a major carbon sink, holding large amounts of methane. That’s the gas trapped in the frozen bubbles seen here. Baikal’s ice is exceptionally clear, making long trails of frozen bubbles visible during the winter. (Image credit:…
Tracking Meltwater Through Flex
Greenland’s ice sheet holds enough water to raise global sea levels by several meters. Each year meltwater from the sheet percolates through the ice, filling hidden pools and crevasses on its way to draining into the sea. Monitoring this journey directly is virtually impossible; too much goes on deep below the surface and the ice…