Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
“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…
Even Mountains Flow
Over about 5 months of 2018, the summit of Mount Kilauea slowly collapsed as the volcano erupted. Seen in timelapse, it’s a remarkable reminder of the ancient Greek philosopher Heraclitus’s observation, “Everything flows.” All things change, so given enough time, just about everything can flow. Fluid dynamicists actually capture this concept in a dimensionless ratio known…
The Sharpshooter Insect
The sharpshooter is a small, sap-sucking insect capable of consuming more than 300 times its body weight in fluid each day. To sustain that level of intake, the insect also has to have a robust mechanism for expelling excess fluid, and that particular talent has earned the insect the nickname of the “pissing fly”. Together a…
Ice Cream Vortex
[original media no longer available] Here’s a fun demonstration of vorticity: sticking an ice cream cone in a bathtub vortex. Now, before someone points out that this is clearly a sink, not a bathtub, the term “bathtub vortex” actually has a standard scientific usage; it’s used to describe a vortex that forms when water drains…
Keeping Bubbles Around
Bubbles don’t stick around in pure water. Surfactants are needed to stabilize the thin liquid film for longer than the blink of an eye. But that’s not necessarily the case for other liquids. As the video below shows, a bubble in isopropyl alcohol is quite stable. This is because of the alcohol’s volatility – its…
Massive Worthington Jet
The FloWave facility in Scotland is one of the coolest ocean simulators out there. Equipped with 168 individual wave makers and 28 submerged flow-drive units, it’s capable of recreating almost any ocean conditions imaginable. So naturally the Slow Mo Guys used it to create a giant spike wave. Essentially, this is an oversized Worthington jet,…