Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Tar Pit, Sweet Tar Pit
The La Brea Tar Pits have delivered countless creatures to their doom over tens of thousands of years. But the sticky quagmire of the pits’ natural asphalt is a comfy home to at least one animal: the petroleum fly. The fly’s maggots secrete a lipophobic — in other words, oil-repelling — fluid that allows them…
“Magic of the North”
Fires glow above and below in this award-winning image from photographer Josh Beames. In the foreground, lava from an Icelandic eruption spurts into the air and seeps across the landscape as it slowly cools. Above, the northern aurora ripples through the night sky, marking the dance of high-energy particles streaming into our atmosphere, guided by…
Dry Plants Warn Away Moths
Drought-stressed plants let out ultrasonic distress cries that moths use to avoid plants that can’t support their offspring. In ideal circumstances, a plant is constantly pulling water up from the soil, through its roots, and out its leaves through transpiration. This creates a strong negative pressure — varying from 2 to 17 atmospheres’ worth —…
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…