Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Desalination in Action
Desalination — the removal of salt from water — is an important process for providing the fresh water we need, but it’s quite expensive in terms of energy. In this Practical Engineering video, Grady demonstrates small-scale versions of the two most common methods for purifying water: distillation and reverse osmosis. In distillation, salt water is…
Understanding Cyanobacteria
Over 2 billion years ago, cyanobacteria emerged as Earth’s first photosynthesizing organisms. Today they are widespread and critical contributors to both carbon and nitrogen cycles. Colonies can form large mats, like those pictured above, but, even at the microscale, cyanobacteria are actively forming patterns among individual bacteria. A recent study considers cyanobacteria as active matter.…
Shifting Sands
Qinghai Lake sits in western China, where a warmer and wetter climate has been raising the lake’s water level in recent years. These two satellite images, from 2010 and 2022, show the effects of those changes. Sand spits that once separated the smaller Shadao Lake from the surrounding lake have worn away and sunk, rejoining…
Swimming Through Mud
At the bottom of ponds, nematodes and other creatures swim in a world of mud. They squirm their way through a sediment of dirt particles suspended in water. Mud, of course, is notoriously impossible to see through, so to understand these creatures’ movements, scientists turn instead to biorobotics. Here, a team uses a magnetic head…
Melting Ice Cap
This award-winning photo by Thomas Vijayan shows waterfalls of ice melt off the Austfonna ice cap. The third-largest glacier in Europe, Austfonna is located in Norway’s Svalbard archipelago. Like other glaciers, it sees rising temperatures and increased melting due to climate change. Vijayan highlights that melting with his focus on the many waterfalls slicing through…
Withstanding Rocket Launches
It takes a lot of power to lift a giant rocket‘s payload all the way to orbit, and in the first moments of a rocket launch, all that energy is directed downward at a concrete pad. How do engineers design and protect launch pads? In this Practical Engineering video, Grady tackles just that question through…
Imitating a Cough
Coughing and sneezing create violent air flows in and around our bodies. As that fast air rushes over mucus layers in our lungs, throat, and sinuses, the resulting flow breaks up the mucus into droplets. To explore the details of that process, researchers built a “cough machine” that sends a rush of air over a…
Lagoon Nebula
Some 4,100 light years away in the Sagittarius constellation, a stellar nursery births new stars. Known as Messier 8, or the Lagoon Nebula, this region is one of the most visible nebulas from Earth. It is filled with turbulent gases and dark strands of dust. Near the centerline of the image is the bright, hourglass…
Leidenfrost Collapse
When a droplet encounters a surface much hotter than its boiling point, it forms a thin layer of vapor that insulates the liquid from the surface. But this Leidenfrost effect can’t last forever. Eventually, the vapor layer destabilizes and the drop touches the surface, causing explosive boiling that destroys the drop. To determine how the…
“Animaris Rex”
Eighteen meters long and powered only by the wind, artist Theo Jansen’s latest Strandbeest strolls the sand in this short video. Its complex movements — a swinging gait in some places and a caterpillar-like wave in others — are mesmerizing and life-like enough to almost make you wonder if the contraption truly is alive. See…