Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Noctilucent Clouds
Noctilucent clouds are the “highest, driest, coldest, and rarest clouds on Earth.” Formed in the mesosphere at altitudes over 80 kilometers, these clouds typically form at polar latitudes where they can catch sunlight hours after sunset, hence their night-shining name. The clouds take shape when water vapor in cold mesospheric air layers freezes onto dust…
Why Creases Don’t Disappear
Flex your fingers and you’ll see your skin fold into well-defined creases. Many soft solids (including old apples) fold this way, and like your skin, the creases never fully disappear, even when the stress is removed. A recent study finds that surface tension and contact-line-pinning are critical to the irreversibility of these creases. The authors…
Cleaning Up Combustion
In space, flames behave quite differently than we’re used to on Earth. Without gravity, flames are spherical; there are no hot gases rising to create a teardrop-shaped, flickering flame. In many ways, removing gravity makes combustion simpler to study and allows scientists to focus on fundamental behaviors. It’s no surprise, then, that combustion experiments are…
Outtakes
When filming, things don’t always go according to plan. Glasses break, splashes obscure your subject, and sometimes effects just don’t turn out the way you expect. But if you’re the Macro Room team, even those mistakes and outtakes are pretty darn fascinating to watch! I especially like some of the granular “splash” sequences here. (Image…
Spiral Shark Intestines
We’ve seen previously just how fluid dynamically impressive sharks are on the outside, but today’s study demonstrates that they’re just as incredible on the inside. Researchers used CT scans of more than 20 shark species to examine the structure of their intestines. Sharks have spiral intestines that come in four different varieties; two of those…
“Feeding the Sea”
It’s impressive when a microscopic organism is visible from space, but that’s a regular occurrence for phytoplankton, the tiny marine algae that feed much of the ocean. In this video from NASA Earth Observatory, we travel around the globe, observing phytoplankton blooms and learning about the ecosystems they feed — or destroy. Note that many…
Megaripples Beneath Louisiana
Approximately 66 million years ago, a 10-km asteroid struck our planet near Chicxulub on the Yucatán Peninsula. The impact was globally catastrophic, causing tsunamis, wildfires, earthquakes, and so much atmosphere-clogging sediment that about 75% of all species on the planet — including the non-avian dinosaurs — died out. A new study points to another remnant…
Sandsculpting Bees
Building sandcastles is more than a pastime for the bumblebee-mimic digger bee. This species of bee collects water into an abdominal pouch, then uses it to wet sand to help her sculpt her nest. She’ll use the material she digs out to create a protective turret over the nest’s entrance, and once her eggs are…
Candy Clouds Mid-Storm
There’s nothing quite like a towering storm cloud to showcase nature’s power. This gorgeous photo by Laura Rowe shows pastel clouds over West Texas in the middle of a thunderstorm. Despite the dusk at ground level, the height of the cloud keeps it lit by direct sunlight, giving its turbulent convection that colorful glow. Rowe,…
Hydrodynamic Spin Lattices
Droplets bouncing on a fluid bath display some strikingly quantum-like behaviors thanks to the interactions between a drop and its guiding surface wave. Here, researchers use submerged wells beneath the drop to confine each droplet into a space where it bounces in a clockwise or anticlockwise trajectory. With an array of these wells, the droplets…