Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Pearls of Mezcal
Mezcal is a traditional Mexican liquor distilled from agave. (The more commonly known tequila is actually a special type of mezcal.) As a part of the production process, distillers pour a stream of mezcal into a bowl, creating a flotilla of small bubbles called pearls. Strange as it sounds, these pearls let the distiller judge…
Viscous Fingers
Viscous fingers form between air and titanium dioxide sol-gel in this photograph. The two fluids are trapped in a thin gap between glass plates – a set-up known as a Hele-Shaw cell. The dendritic fingers we see form when the less viscous air pushes into the more viscous sol-gel. This is an example of the…
Fluids Round-Up
Time for another fluids round-up! Here are some of the best fluids-related links I’ve seen around: – Above The Brain Scoop tells us about beetles that spend their whole lives underwater. They carry a little bubble of air with them in order to breathe! – Microfluidics are helping reveal how cancer cells metastasize and spread…
Roll Clouds
The roll cloud, or Morning Glory cloud, is a rare phenomenon that looks rather like a horizontal tornado. In reality, it is part of a soliton wave traveling through the atmosphere. At its leading edge, moist air is forced upward, causing water vapor to condense, and, at the trailing edge, air moves downward, dissipating the…
Boiling on Mars
Today’s Mars is cold and dry, with a thin and insubstantial atmosphere. One of the challenges facing planetary scientists is unraveling the processes behind the complex terrain we can observe on the surface. Without flowing water, how do we explain these features? A new experiment suggests that the answer lies in boiling. Surface conditions on…
Silent Flying
As nocturnal hunters, owls are aerodynamically optimized for stealthy flying. This clip from BBC Earth demonstrates just how quiet a barn owl is in flight compared to a pigeon or a peregrine falcon. The owl’s large wingspan relative to its body size gives it enough lift that it does not have to flap often, allowing…
The Bubble Nebula
This spectacular Hubble image shows the Bubble Nebula. The source of this nebula is the star seen toward the upper left side of the bubble. This massive, super-hot star has ceased to fuse hydrogen and is now fusing helium, powering its way to a likely end as a supernova. As it burns, the star emits…
Striking Oobleck
Mixing cornstarch and water creates a fluid called oobleck that has some pretty bizarre properties. Oobleck is a shear-thickening, non-Newtonian fluid, which means its viscosity increases when you try to deform it with a shearing, or sliding, force. But as the Backyard Scientist demonstrates above, striking oobleck with a solid object produces some spectacular and…
Emulsion Impact
Emulsions – mixtures of two immiscible fluids – are quite common; the oil and vinegar combination used in many salad dressings is one. The image sequence above shows the first 800 microseconds of the impact of a similarly emulsified droplet. The outer drop, seen on the left, consists of a water/glycerin mixture, and inside the…