Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Soaring Through the Pillars of Creation
The Pillars of Creation are an iconic feature nestled within the Eagle Nebula. For decades, the public has admired Hubble’s images of this stellar nursery, and, in this video, we get to fly between the pillars, shifting between Hubble’s visible light imagery and JWST’s infrared views. In visible light, glowing dust obscures the interior of…
Active Cheerios Self-Propel
The interface where air and water meet is a special world of surface-tension-mediated interactions. Cereal lovers are well-aware of the Cheerios effect, where lightweight O’s tend to attract one another, courtesy of their matching menisci. And those who have played with soap boats know that a gradient in surface tension causes flow. Today’s pre-print study…
Revealing Gravity Waves
Severe weather — like thunderstorms, tornadoes, and hurricanes — can push air upward into a higher layer of the atmosphere and trigger gravity waves. Aboard the International Space Station (ISS), the Atmospheric Waves Experiment (AWE) instrument captures these waves by looking for variations in the brightness of Earth’s airglow (above). Recently, when Hurricane Helene hit…
Beneath a River of Red
A glowing arch of red, pink, and white anchors this stunning composite astrophotograph. This is a STEVE (Strong Thermal Emission Velocity Enhancement) caused by a river of fast-moving ions high in the atmosphere. Above the STEVE’s glow, the skies are red; that’s due either to the STEVE or to the heat-related glow of a Stable…
Inside the Squirting Cucumber
Though only 5 cm long, the squirting cucumber can spray its seeds up to 10 meters away. The little fruit does so through a clever combination of preparation and ballistic maneuvers. Ahead of launch, the plant actually moves water from the fruit into the stem; this reorients the cucumber so that its long axis sits…
Glacial Tributaries
Just as rivers have tributaries that feed their flow, small glaciers can flow as tributaries into larger ones. This astronaut photo shows Siachen Glacier and four of its tributaries coming together and continuing to flow from the top to the bottom of the image. The dark parallel lines running through the glaciers are moraines, where…
A Seismic Warning for the Tongan Eruption
In mid-January 2022, the Hunga Tonga-Hunga Ha’apai (HTHH) volcano had one of the most massive eruptions ever recorded, destroying an island, generating a tsunami, and blanketing Tonga in ash. Volcanologists are accustomed to monitoring nearby seismic equipment for signs of an imminent eruption, but researchers found that the HTHH eruption generated a surface-level seismic wave…
Wave Clouds in the Atacama
Striped clouds appear to converge over a mountaintop in this photo, but that’s an illusion. In reality, these clouds are parallel and periodic; it’s only the camera’s wide-angle lens that makes them appear to converge. Wave clouds like these form when air gets pushed up and over topography, triggering an up-and-down oscillation (known as an…
“Paradolia”
In “Paradolia,” filmmaker Susi Sie plays with pareidolia, our tendency to seek patterns in nebulous data — like faces on a slice of toast. Droplets of miscible and immiscible fluids collide, part, and mix in each sequence, providing plenty of fodder for an active imagination. For myself, my brain especially likes assigning cartoon expressions to…
Inside a Big Cat’s Roar
The roars of big cats — tigers, lions, jaguars, and leopards — carry long distances. In part, this reflects the animals’ size: large lungs exhale lots of air through a large voice-box, whose vibrations resonate in a large throat. But size alone does not make the roar. Below are examples of two big cat voice-boxes.…