Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Enormous Ice Disk
We’ve seen spinning ice disks before, but this month Westbrook, Maine has developed the largest one I’ve ever seen. A research paper from 2016 indicates that this seemingly alien formation spins due to an oddity of water. Water is at its densest around 4 degrees Celsius, so as the ice of the disk melts in the…
An Inverted Leidenfrost Drop
Leidenfrost drops – liquid drops that levitate on a layer of their own vapor over a hot surface – have been all the rage in recent years. We’ve seen how they can be guided, trapped, and self-propelled. What you see here is a bit different. This is a droplet of room-temperature ethanol deposited on a…
The Boston Molasses Flood
Today marks the 100th anniversary of the Boston Molasses Flood, and to commemorate this bizarre disaster, I’ve made a video about the key findings from my research with colleagues at Harvard University. Check it out below! And, if you’re still hankering to learn more about the Molasses Flood, here are some recent articles and interviews…
Lava Bomb
What you see above is a homemade lava bomb. To systematically study what happens when groundwater meets lava, scientists melted basalt and created their own meter-scale explosion-on-demand. Inside the container, they can inject water and observe the resulting dynamics. Beneath the lava, the water forms what scientists call a domain. Thanks to the Leidenfrost effect,…
“The Empire of C”
Filmmaker Thomas Blanchard has once again released a beautiful, fluid-filled short to captivate us. Built from paint, oil, and liquid soap, “The Empire of C” feels like it gives viewers a birds-eye perspective over a fantastical land. I was particularly drawn to two fluid dynamical aspects of the film. The first were the dendritic sequences in…
Dip Coating
Imagine dipping a rod into a liquid mixture filled with particles. When you pull the rod out, do particles stick to it? The answer depends on the relative importance of two sets of forces: the viscous drag as you lift the rod and adhesive power of surface tension. Scientists express this as a dimensionless ratio…
Water Anoles Breathe Underwater
Meet the water anole, a small lizard native to the tropics of Central America. While studying these anoles, researchers discovered that they could flee underwater and remain submerged for 16 minutes or more at a time. Curious to see how the lizard manages this feat, they filmed them underwater, discovering that the anole seems to…
Sonic Tractor Beam
Acoustic levitation uses the radiation forces generated by sound waves to trap small, lightweight particles at the nodes of standing waves. We’ve seen this a number of times previously, both with solid objects and liquid droplets. What makes this example particularly impressive, though, is that these researchers use an array of speakers to manipulate multiple…
Finding New Shapes in Foam
In the summer of 2018, a group of researchers announced they’d discovered a new geometrical shape, the scutoid. They found the scutoid, a sort of twisted prism, in the shape of epithelial cells packed between curved surfaces. Having heard of this new geometry, a different group of physicists wondered if they could find scutoids elsewhere,…
Vortices and Ground Effect
Though typically unseen, the vortices that swirl from the tips of aircraft wings are powerful. Here you see a Hawker Sea Fury equipped with a smoke system used to visualize the vortices that form at the wingtip as high-pressure air from the bottom of the wing and low-pressure air from the top swirl together. As…