Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
How the Hagfish Deploys Its Slime
Hagfish – an eel-like species – are known for their prodigious slime production, which helps them escape predators (and, in some cases, seriously muck up highways). Part of the hagfish’s slime consists of ~10 cm fibers that the creature deploys in tiny skeins (bottom) only a hundred microns across. To form the viscoelastic slime that…
Viscoelasticity and Liquid Armor
One proposed method for improving bulletproof armor is adding a layer of non-Newtonian fluid that can help absorb and dissipate the kinetic energy of impact. Thus far researchers have focused on shear-thickening fluids – like cornstarch-based oobleck – filled with particles that jam together if anything tries to deform them quickly. But is it really…
Sorting Blood Cells
Many diseases – like sickle-cell anemia and malaria – are accompanied by changes in the stiffness of red blood cells. And while microfluidic devices capable of sorting blood cells by size exist, few have made microfluidic devices capable of sorting blood cells by their deformability. But a new set of simulations suggests we could do…
Melting
File this one under “Oddly Satisfying” – this timelapse video shows the process of melting a jawbreaker candy using a blowtorch. Over a minute and a half, each colorful layer of candy melts away to reveal the strata beneath. There’s a definite connection here to some of the previous research we’ve discussed on erosion, dissolution, and…
Noisy Jets
One major problem that has plagued supersonic aircraft is their noise. The Concorde – thus far the only supersonic commercial airliner – was plagued with noise complaints that ultimately restricted its usability. Noise reduction is a major area of inquiry in aerospace, and the video below shows one experiment trying to understand the connections between…
“The World Below”
Since the first cosmonauts and astronauts entered orbit around our planet, they’ve held a unique perspective. Thanks to the timelapse photography of recent astronauts aboard the ISS and the editing skills of photographer Bruce W. Berry, Jr, the rest of us can enjoy a taste of that viewpoint. Turn up the volume, fire up the…
Bats in Ground Effect
As pilots can tell you, flying near the ground (or an open expanse of water) gives one an aerodynamic boost. Essentially, the surface acts like a mirror, reflecting and dissipating the wingtip vortices that create downwash. That reduces the power necessary to fly, as long as you’re flying within about a wingspan of the surface.…
Inside a Wind Tunnel
When I was in graduate school, I worked in a facility known as the High-Speed Wind Tunnel Lab. We were located next door to the Low-Speed Wind Tunnel, and every few months we’d receive a phone call asking whether we could film someone in the high-speed wind tunnel. This was impossible for several reasons –…
Patterns of Flame
In nature, the way a system behaves often depends on multiple competing factors. This is particularly apparent for chemical reactions, some of of which can oscillate in wild patterns as different forces compete. Similar patterns can occur in combustion, as shown above. What you see here are patterns formed on a flame propagating down a…