Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Droplets Through a Forest
When droplets flow through a forest of microfluidic posts, they can deform around the obstacle or break up into smaller droplets. Here, researchers explore the factors that control the outcome, as well as when droplets collide, coalesce, and mix. (Video and image credit: D. Meer et al.)
“Moment of Creation”
Bubbles caught in ice resemble the growth of a cellular organism in this photograph of Tatiewa Lake in Japan, taken by Soichiro Moriyama. When water freezes, gases dissolved in it come out of solution, but depending on the speed and direction of freezing, these bubbles do not always escape before ice forms around them, freezing…
Ripple Bugs
Ripple bugs are a type of water strider capable of moving at a blazing fast 120 body lengths per second across the water surface. In addition to their speed, ripple bugs are incredibly agile and are active almost constantly. Researchers believe they’ve found the insect’s secret: feather-like hydrophilic fans that spread on contact with the…
Leaves Dance in the Wind
Once a breeze kicks up, leaves on a tree start dancing. Every tree’s leaves have their own shapes, some of which appear very different from other trees. But their dances have patterns, as this video shows. In it, researchers explore how leaves of different shapes deform in the wind and how they can decompose that…
Panama’s Missing Pacific Upwelling
Strong seasonal winds blowing from the Atlantic typically push water away from Panama’s Pacific coast, allowing deeper, colder waters to rise up. This upwelling cools reefs and feeds phytoplankton blooms, both of which support the rich marine life found there. But in early 2025, the upwelling didn’t occur. Normally, coastal ocean temperatures drop to about…
A Soft Cell in Microgravity
There are many shapes that can be tiled to fill space, but nearly all of them have sharp corners. Last year, mathematicians identified a new class of shapes, known as “soft cells,” that feature curved edges and faces but very few sharp corners. Like traditional polyhedrals, soft cells can tile to fill a space completely…
“Legends of the Falls”
Strong winds blew curtains of mist across Skógafoss in this image of nesting northern fulmars by photographer Stefan Gerrits. Despite water’s high density compared to air, fine droplets are able to stay aloft for long periods, given the right breeze. Mists, fogs, and sea spray can float surprising distances; droplets exhaled from our lungs can…
Controlling Hovering
Hummingbirds and many insects hover when feeding, escaping predators, and mating. While scientists have decoded the mechanics of a hummingbird’s figure-8-like hovering wingstroke, it’s been harder to understand how the creatures control their hovering. Most of our attempts to control hovering require more computational power than hummingbirds and insects are thought to have. But this…
Marangoni Bursting With Surfactants
A few years ago, researchers described how an alcohol-water droplet atop an oil bath could pull itself apart through surface tension forces. Dubbed Marangoni bursting, this phenomena has shown up several times since. Here, researchers explore a twist on the behavior by adding surfactants to see how they affect the bursting phenomenon. (Video and image…
Acoustically Trapping Nanoparticles
Micrometer-sized particles can be trapped in place against a flow using acoustic waves. But smaller nano-sized particles feel less radiation pressure from acoustic waves, and so keep moving in the flow. But new work shows that it is possible to trap those nanoparticles with some additional help. In this case, researchers seeded their flow with…