Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Water Impacts
In the clean and simplified world of the laboratory, a droplet’s impact on water is symmetric. From a central point of impact, it sends out a ring of ripples, or even a crown splash, if it has enough momentum. But the real world is rarely so simple. Here we see how droplets impact when the…
Rogue Waves
After centuries of tales from sailors, in 1995 the Draupner off-shore platform recorded the first ever evidence of a freak wave – a single, wall-like wave steeper and taller than any other waves around it. Theories have been tossed back and forth for the last quarter century as to how the Draupner wave formed, but…
Moving Droplets
Microfluidic devices – such as those used by individuals with diabetes to monitor their blood glucose levels – are all about transport. Typically, these devices use some kind of externally applied force, like a temperature gradient or electrical field, to force liquids through the device’s narrow channels. But a new study describes a way to…
Freezing Drop Impact
At the altitudes where aircraft fly, it’s often cold enough for water drops to freeze in seconds or less. Once attached to a wing, such frozen drops disrupt the flow, reducing lift and increasing drag. To help understand how such droplets freeze, scientists study droplet impact on cold surfaces. Starting at room temperature (counter-clockwise from…
Sniffing
In many ways, smell is a strange sense. The very act of sniffing – pulling air and odor molecules into our noses – changes what remains behind in a way that sight and sound do not. Humans aren’t great sniffers, but dogs have an exquisite sense of smell, and in this video, Deep Look describes…
Putting a Spin on Splashes
Researchers put a spin on splashing droplets with selective wetting. When a drop impacts on a water-repellent, superhydrophobic surface, it will spread circularly, then pull back together and rebound off the surface. That’s because the surface coating resists actually touching – or being wetted by – the water. But just as there are surface coatings…
Catching Prey
The skinny, freshwater alligator gar can grow to more than 2 meters in length, giving it a distinct resemblance to its namesake. But this fish’s history traces back more than a hundred million years to the Early Cretaceous. And a new (pre-printed) study, combining live observations and numerical models built from CT-scans, is shedding new…
Magma Mixing
Magmas typically consist of a mixture of molten liquid, bubbles, and solid crystals. As they mix, those crystals can sink from one viscous layer into another. To investigate this sort of process, researchers studied solid particles sinking across an interface between two viscous liquids. This is what we see above. One fluid is clear; the…
Slow Mo Geyser
Geysers are one of the most surreal wonders of our planet – pools of turquoise that periodically erupt into towers of water and steam. But what we see from the surface is only a small part of the story. Geysers require two main ingredients: an intense geothermal heat source and the right plumbing. Below ground,…
Seeing Shock Waves
This week NASA released the first-ever image of shock waves interacting between two supersonic aircraft. It’s a stunning effort, requiring a cutting-edge version of a century-old photographic technique and perfect coordination between three airplanes – the two supersonic Air Force T-38s and the NASA B-200 King Air that captured the image. The T-38s are flying…