Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How Methane Bubbles End Up in Steel
We typically think of a chunk of metal as being solid and unchanging. Maybe you get a little oxidation on the outside surface, but everything stays the same inside, right? As Steve Mould explains in today’s video, in some applications, the situation isn’t that simple. In particular, steel is vulnerable to hydrogen gas squeezing in…
In the Tidal Zone
A lone shark cruises a sandy shoreline in the Maldives in this image from photographer Tim Burgess. Its path parallels the footsteps left by humans on the beach. Between the beach’s sand and the ocean’s deeper water, there’s a narrow stripe of sand ripples. Constantly formed and reformed by the crashing waves, these ripples act…
Espresso Under Pressure
When a fluid flows through a porous bed of grains–like sand, soil, or coffee grounds–the flow rate typically increases linearly with pressure. But that’s not the case for espresso, which is typically brewed with 6-9 bars of pressure. Instead, espresso’s flow rate plateaus at around 5 bars, stays constant as pressure increases, and then drops…
Stick Insects in Flight
There’s something about watching big, awkwardly-shaped insects taking off that doesn’t get old. In this video from Ant Lab, we see giant stick insects spreading their wings and taking off. It’s interesting to note that they seem to be wing-first in their take-off; it doesn’t look like they’re doing much, if anything to propel themselves…
Snails Tune Their Slime
Snails have a mucus for every occasion. The grove snail/lemon snail makes five different varieties: one for lubricating its motion, one for adhering to surfaces, one to seal it in its shell for winter, and two to protect against predators. A new study looks at how those different types of mucus differ. The basic building…
Rayleigh-Taylor Instability
When a heavier fluid sits atop a lighter one, the interface between them can be unstable. This means that even a very slight disturbance will be enough to cause fingers of dense (dark) fluid to sink while fingers of the lighter (white) fluid rise. This is known as the Rayleigh-Taylor instability, and it’s responsible for all…
Urinal Dynamics Win Ig Nobel Prize
Thirteen years ago, I made a prediction that work on how to avoid urinal splashback would win an Ig Nobel Prize. Today, I am, at last, vindicated. Randy Hurd, Zhao Pan, Tadd Truscott, and Kaveeshan Thurairajah shared the 2026 Ig Nobel Prize in Physics for their work designing a splash-free urinal. The culmination of this…
Liquid Flow on Pluto
When New Horizons flew by Pluto, the dwarf planet’s bright heart-shaped glacier at Sputnik Planitia garnered much attention. Now scientists think they’ve found evidence that liquid has flowed recently there. In a new study, they argue that dark regions near the glacier’s edge are likely places where liquid nitrogen flows up through the nitrogen ice…
Understanding Hurricane Katrina’s Floods
Hurricane Katrina’s storm surge flooded roughly 80% of New Orleans when multiple levees breached. In this video, Grady of Practical Engineering breaks down the engineering failures that made Katrina’s flooding so bad. In his typical hands-on fashion, he shows the flaws of the I-wall-topped levee design, and he takes the time to detail how the…
Kelvin-Helmholtz Waves on the Sun
When it comes to how stars like our Sun work, scientists have long relied on theoretical predictions to describe processes we couldn’t observe firsthand. But new images from our most powerful solar telescope have finally revealed a phenomenon that’s long been predicted: Kelvin-Helmholtz waves on the Sun’s photosphere. Even if the name is unfamiliar, you’re…