Sometimes the best way to appreciate a flow is standing still. In “Hawaii – The Pace of Formation” filmmakers explore how the Big Island is constantly changing, from fresh lava flows to towering waterfalls. Much of the footage presented is timelapse, which gives viewers a different perspective on familiar subjects; it highlights the similarities between clouds and the ocean, and it reminds us that a lava flow and the syrup flowing down a stack of pancakes have a lot in common. To me, this is one of the most beautiful parts of fluid dynamics: physics of flows on different length-scales and time-scales – even in different fluids – are still very much the same. (Video credit: A. Mendez et al.)
Category: Art
Fanning the Flame
A fan’s blade passes through the hot air rising above a flame in this iconic image by high-speed photography pioneer Harold Edgerton. This photo uses an optical technique known as schlieren photography that makes density differences in transparent media like air visible. Because of its lower density, the hot plume of air above the flame rises. When the fan blade swings past, it sheds a vortex off its tip and the rising air from the flame gets pulled into the vortex to make it visible. To the left, a ghostly counter-rotating vortex sits on the opposite side of the fan blade. (Photo credit: H. Edgerton and K. Vandiver)
Breaking Wave
This animation shows a cinemagraph of a breaking wave photographed by Ray Collins. The motion was inferred and digitally added by a second artist, Jersey Maria. The result is hypnotic, as if we are traveling beside the wave and watching it tear apart ever so slowly. The wave seems to be poised on a tipping point, only breaking up along its back edge, when instinct tells us it will keep steepening and tipping forward until its top curl crashes down in a wave of white foam. Surf photography like Collins’ work shows us an alternative perspective on waves, their power frozen into a single instant. Reanimated, it feels like we’re seeing the wave in hyper-slow-motion, watching every tiny movement of water before everything crashes down. Even if it’s not physically realistic, it is an awesome view. (Image credit: R. Collins / J. Maria, source, original; via Iwan A.)
Acrylic and Oil
Photographer Alberto Seveso is well-known for ink in water art, some of which FYFD has featured previously (1, 2, 3). More recently, he’s been experimenting with alternative methods, dropping fluids like acrylic paint into sunflower oil. The effect is quite different but no less beautiful. Because the paint and oil are immiscible, the boundaries between the two fluids are much more clearly defined and highlighted in an iridescent sheen. Instead of appearing like billowing waves of silk, the paint forms abstract and alien shapes driven by gravity, inertia, and density differences. For many more great examples, check out Seveso’s website. (Photo credit: A. Seveso)
Breaking Soon
Australian photographer Warren Keelan captures spectacular photos of waves just before and during the moment they break. Fluid dynamics is defined by motion – specifically the motion of substances that do not hold a single form – but one thing I love about wave photography is how crisp and solid water appears when frozen in time. In a way, it feels like a reminder that, even though we classify matter into different states, ultimately those states have a lot in common. (Image credit: W. Keelan; via Colossal)
Freezing Bubbles
Soap bubbles are wonderfully ephemeral, their surfaces constantly in motion as air currents, surface tension variations, and temperature differences make them dance. In this video, though, photographer Paweł Załuska focuses on freezing soap bubbles. Watching the growth of ice crystals across the bubbles’ thin surface is mesmerizing. Snowflake-like crystals can nucleate anywhere on the film and, as in the sequence at 0:48, those crystals can float around on the bubble’s surface like snowflakes drifting on a breeze until enough of the film solidifies to bring the bubble to a halt and, then, a collapse. (Video credit: P. Załuska/ZALUSKart; via Gizmodo)
Soap Bubbles Up Close
Watching soap bubbles up close is endlessly fascinating. The iridescent colors reflect the soap film’s thickness, or, in the case of black spots, its lack thereof. The dancing of the colors shows the soap film’s flow and the ever-shifting balance of surface tension necessary to keep the film intact. Even the junctures of the bubbles–so precise and mathematically perfect in structure–reflect the molecular interactions that govern them. (Video credit: Stereokroma; via R. Weston)
Weather Posters
Weather Underground has created a whole series of posters celebrating and briefly explaining various weather phenomena. Many of their subjects are beautiful and unusual types of clouds like the lenticular clouds that form over mountains and hole-punch clouds created when supercooled water vapor gets disturbed. They have a few non-cloud phenomena we’ve discussed previously, too, such as dust devils and bizarre, wind-formed snow rollers. I highly encourage you to check out the full collection, which they’ve made available as phone and computer wallpapers as well as posters. Personally, these combine two of my favorite things: fluid dynamics and retro-style nature posters! (Image credit: Weather Underground)
“Pulse”
Photographer Mike Olbinski returns with another incredible storm-chasing timelapse video, this time all in black-and-white. To me, that choice helps “Pulse” emphasize the ominous majesty of these supercells and tornadoes by highlighting the textures that make up the clouds. Watching clouds in timelapse, they seem to materialize from nowhere as moisture drawn up from the land cools and condenses. Sped up, suddenly the convective rotation and the roiling turbulence inside clouds is perfectly clear. I especially love the sequence beginning at 2:25, where a distant black line slowly transforms into an incredible landscape marked with successive waves of rolling, turbulent clouds. Watch this one on a large screen at a high resolution, if you can. You won’t regret it! (Video credit: M. Olbinski)
“Kingdom of Colours”
Oil, paint, and soap combine to create a polychrome landscape in Thomas Blanchard’s “Kingdom of Colours” short film. Colorful droplets of paint coated in oil form anti-bubbles that skim along the liquid surface until they burst, dispersing new colors. One of my favorite touches in this video, though, are the branching fingers of color that appear repeatedly (most often in blue-violet). This is an example of a phenomenon known as the Saffman-Taylor instability. It’s a hallmark of a low viscosity fluid pushing into a higher viscosity one–like air into honey. (Image/video credit: T. Blanchard; via Flow Vis)
