Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Elastic Turbulence
Decades ago, engineers pumping polymer-filled drilling liquids into porous rock noticed sudden and dramatic increases in the viscosity of the liquid. Within the tiny pores of the rock, conventional (i.e., inertial) turbulent flow should be impossible — the Reynolds number is simply too low. Now a new experiment points to the source of the high…
The Yarning Droplet
Marangoni bursting takes place in alcohol-water droplets; as the alcohol evaporates, surface tension changes across the liquid surface, generating a flow that tears the original drop into smaller droplets. Here researchers add a twist to the experiment using PMMA, an additive that dissolves well in alcohol but poorly in water. As the alcohol evaporates, the…
Viscosity and Quantum Mechanics
Viscosity describes a fluid’s resistance to changing its shape. Like surface tension, it’s a fundamental property of a fluid that comes from the interactions between molecules. But viscosity is a slippery beast, and especially so for liquids. There is no generic way to calculate a liquid’s thermodynamic properties from quantum dynamical first principles. But that…
Moody Waves
Lines of waves emerge from thick morning fog in this series by photographer Raf Maes. The eerie, slightly surreal images were captured in Venice, near Los Angeles. So often ocean photography features huge, turbulent breaking waves. I find it really neat to see these long, unbroken wave crests appearing from the mist. (Image credits: R.…
The Return of the Ice Disk
Maine’s giant, spinning ice disk is taking shape again. In 2019, it reached about 91 meters across, rotating slowly in the Presumpscot River. How exactly these features form is still a matter of debate, but scientists have worked out a few relevant mechanisms. The spinning of the disk seems to depend on a vortex that…
Laser-Induced Jet Break-Up
A falling stream of water will naturally break up into droplets via the Plateau-Rayleigh instability. Those droplets are random, unless something like vibration of the nozzle sets their size. In this study, though, researchers found that shining a laser beam on the stream can trigger an orderly break-up with droplets that are consistent in size…
Volcanic Shocks
A violent underwater eruption at the Hunga Tonga-Hunga Ha’apai caldera on January 15th sent literal shock waves around the world. This animation, based on satellite images from Japan’s Himawari 8, shows the fast-moving shock waves and the growing ash plume coming from the uninhabited island. Although most recent eruptions from this volcano have been small,…
Changing with the Flow
Chemically-reacting flows are some of the toughest problems to unravel. In this new study, researchers found that the very act of flowing through narrow channels can change the speed of chemical reactions. In particular, they found that protein molecules carried through a capillary tube (comparable in size to human capillaries) changed their local shape as…
“One Month of Sun”
Get lost in the beauty of our star with Seán Doran‘s film “One Month of Sun”. Constructed from more than 78,000 NASA Solar Dynamics Observatory images, the video shows solar activity from August 2014, particularly the golden coronal loops that burst forth from the sun’s visible surface. These bursts of hot plasma follow the sun’s…
Cracking Droplets
Droplets infused with particles — like coffee — can leave complex stains once they evaporate. Here researchers show the complex cracking pattern that develops as a droplet with nanoparticles evaporates. The central image in the poster actually shows the drop’s pattern changing in time. The initial drop is shown at 9 o’clock, and as you…