- Profile
“Perfect Sky”
It’s all blue skies in Roman De Giuli’s short film, “Perfect Sky.” Created with paint, ink, and glitter on paper, it’s a relaxing piece of fluid art. Put on your headphones, take a deep breath, and plunge in. You’ll see lots of gorgeous Marangoni effects, some low Reynolds number mixing, and various instabilities. (Video and…
The Unusual Auroras of Mars
Earth, Saturn, and Jupiter have auroras at their poles, generated by the interaction of their global magnetic fields with the solar wind. Mars has no global magnetic field, only remnants of one frozen into areas of its crust; yet it, too, has auroras. Mars’s auroras are rarer and discrete. They occur most often over the…
Tracking Break-Up
In fluid dynamics, researchers are often challenged with complicated, messy flows. With so much going on at once, it’s hard to work out a way to keep track of it all. Here, researchers are looking at the break-up of two colliding liquid jets. This setup is often used to break rocket fuel into droplets prior…
Eel-Like Swimming
Working with living creatures can’t always reveal their mechanics. That’s one reason engineers like building biorobots. Here, researchers built 1-guilla, an eel-like swimmer, and studied how its body motions affected its swimming. Eels are anguilliform swimmers that use a traveling wave moving along their body from head to tail for propulsion. In the video (and…
Shredding Gold
While vacuums can do pretty wild things to liquids, the title of this Slow Mo Guys video is a bit misleading. They’re not so much exploding gold in a vacuum as they are shredding it during repressurization. Regardless, the visuals are pretty awesome. They place thin foils in a vacuum chamber, pump it down, and…
“-37F Winter in Yellowstone”
Yellowstone National Park is always fascinating and surreal, but especially so in winter when volcanically-heated geysers and springs meet frigid, snowy weather. This short film from Drew Simms shows the park and its wildlife in the depths of winter. The bison rely on thick, shaggy fur coats to trap heat and keep dry. Steam and…
Feynman’s Sprinkler Solved
In graduate school, my advisor introduced us to a particularly vexing fluid dynamical thought experiment known as the Feynman sprinkler. After observing an S-shaped sprinkler that rotated when water shot out its arms, physicist Richard Feynman wondered what would happen if the device were placed in a tank of water with the flow reversed. If…
Seeding Clouds
In the remote South Atlantic, north of the Antarctic Circle, sit the volcanic Zavodovski and Visokoi islands. Though only roughly 500 and 1000 meters tall, respectively, each island disrupts the atmosphere nearby, often generating cloudy wakes. In today’s pair of images, the northerly Zavodovski has a particularly bright cloud wake, thanks to sulfate aerosols degassing…
Stretching Ant Rafts
In their natural habitat, fire ants experience frequent floods and so developed the ability to form rafts. Entire colonies will float out a flood in a two-ant-thick raft anchored to whatever vegetation they can find. Because ants in the upper layer of the raft are constantly milling about, the rafts have some ability to “self-heal”…
Spreading Frost
Condensation forms beads of water on a surface. When suddenly cooled, those drops begin to freeze into frost. This video looks at the process in optical and in infrared, revealing the patterns of spreading frost and the tiny ice bridges that link one freezing drop to the next. (Video and image credit: D. Paulovics et…