Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Dust Devils
Dust devils, like fire tornadoes and waterspouts, form from warm, rising air. As the sun heats the ground to temperatures hotter than the surrounding atmosphere, hot air will begin to rise. When it rises, that air leaves behind a region of lower pressure that draws in nearby air. Any vorticity in that air gets intensified…
Martian Ripples
Earth and Mars both feature fields of giant sand dunes. The huge dunes are shaped by the wind and miniature avalanches of sand, and their surface is marked by small ripples less than 30 centimeters apart. These little ripples are formed when sand carried by the wind impacts the dunes. But Martian dunes have a second,…
These Invertibrates May Help Robots Swim
New FYFD video! Learn all about salps, vortex rings, and underwater robots. Thanasi Athanassiadis takes me inside his lab and his newly published research into how proximity affects the thrust two vortex rings can produce. There are a ton of little things I love about how this video came out, especially the chalkboard animations. Check…
Quarry Smashing
Despite appearances, this is not a crashing ocean wave. In fact, it’s a planned explosion at a quarry, and that wave is more than 360,000 tons of rock and 68 tons of explosive pouring down. The scale of this is hard to imagine, and the physics of a ocean breaker and a massive wave of…
The Knuckleball
For more than a century, athletes have used the zigzagging path of a knuckleball to confound their opponents. Knuckleballing is best known in baseball but appears also in volleyball, soccer, and cricket. It occurs when the ball has little to no spin. The source of the knuckleball’s confusing trajectory, according to a new study, is…
Granular Plugs
Imagine filling a narrow tube with a mixture of water and tiny glass beads. Then take a syringe and very slowly start drawing out the water. As the water gets sucked out of the tube, air will be pulled into the opposite end. The meniscus where the air and water meet sweeps up the glass…
“Vorticity”
Photographer Mike Olbinski is back with another storm-chasing timelapse entitled “Vorticity”. Like his previous work, this film is a breath-taking example of physics in action. It is well worth taking a few minutes to watch in fullscreen, at high resolution, and with headphones. Olbinski’s timelapses beautifully capture the incredible dynamic motion of our atmosphere. Fittingly, “Vorticity”…
The Seabird That Can’t Get Wet
Unlike most seabirds, the frigatebird does not have waterproof feathers. Landing in the water during a transoceanic flight would quickly drown the bird, so instead they stay aloft. But until recently, scientists did not realize just how adept the birds are. Studying tagged frigatebirds in flight, researchers found that the birds could reach altitudes of…
Reader Question: Blood Jets
Reader shoebill-san asks: are blood jets realistic? when someone gets shot in the movies? This one’s a bit tough to boil down to a yes or a no, honestly. While piercing an artery can cause jetting (more on that below), movies tend to exaggerate the effect. And even among Hollywood movies, there’s a broad variation in…
Reversing Time
Waves contain lots of information. They are also time invariant, which means that they will behave the same regardless of whether time moves forward or backward. This isn’t a property we observe often in life since time just moves forward for us. But a new experiment has demonstrated a method of wave control that can,…