Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Different Kinds of Boiling
When you put a pot of water on to boil, you probably don’t give much thought to the process. In our daily lives, we pretty much only see one kind of boiling: the sort where lots of small bubbles form on a hot surface and then rise. That’s nucleate boiling (top image), and it’s typical…
“Muses”
What looks like Baroque paintings are, in fact, underwater photographs in Christy Lee Rogers’ new “Muses” series. By photographing her models underwater at night, Rogers creates a unique, almost dream-like atmosphere that owes its effect to the interplay of light and water. The billowing fabric and chaotic motion come from the water itself, and the dramatic…
Heating from Cavitation
When cavitation bubbles collapse, they can produce temperatures well over 2,000 Kelvin. Since cavitation near a surface can be so destructive, researchers have long wondered whether the high temperatures inside the bubble can be transmitted to nearby surfaces. A new set of numerical simulations provides some insight into that process. The researchers found that collapsing…
Visualizing Aerosols
Aerosols, micron-sized particles suspended in the atmosphere, impact our weather and air quality. This visualization shows several varieties of aerosol as measured August 23rd, 2018 by satellite. The blue streaks are sea salt suspended in the air; the brightest highlights show three tropical cyclones in the Pacific. Purple marks dust. Strong winds across the Sahara…
Antibubbles
Antibubbles are peculiar and ephemeral creations. A bubble typically encloses a gas within a thin layer of fluid. As the name suggests, an antibubble does the opposite: it’s a thin film of gas enclosing a liquid droplet within a larger background liquid. That thin gas film makes antibubbles extremely delicate. Disturb it at all –…
The Driver of Hydraulic Jumps
You’ve seen it a million times. When you turn on your kitchen faucet, the falling water forms a distinctive ring – known as a hydraulic jump – in the bottom of your sink. First described by Leonardo da Vinci, this phenomenon has been studied for centuries, and, for nearly all of that time, scientists assumed…
Why Fish Don’t Freeze
Have you ever wondered why it is that fish in a pond or lake don’t freeze during the winter? The secret is due to a peculiarity of water that’s vital for life here on Earth. In general, cold things are denser than warmer ones. This is why, for the most part, cold fluids tend to…
Bringing the Stars Home
One of my favorite aspects of fluid dynamics is the way that the same patterns and phenomena appear over and over again – sometimes in the most unexpected places. That’s the theme of my new article in American Scientist, which focuses on the connections between our daily lives and the stars: “Solar energy arises from…
The Jumping Flea
Nearly every lab has a magnetic stirrer for mixing fluids, but this ubiquitous tool still holds some surprises, like its ability to unexpectedly levitate. Magnetic stirrers consist of two main parts, a driving magnet that creates a rotating magnetic field, and a bar magnet – commonly referred to as the flea – that is submerged…
Zones and Stars
Large-scale rotating flows, like planetary atmospheres, tend to organize themselves into zones. Within a zone, flow remains essentially in an east-west direction and serves as a barrier that keeps heat or other elements from mixing from one zone to another. This is, for example, how the tropical trade winds work here on Earth. Stars, on…