FYFD

Tag: science

  • The Best of FYFD 2023

    The Best of FYFD 2023

    A fresh year means a look back at what was popular last year on FYFD. Usually, I give a numeric list of the top 10 posts, but this year the analytics weren’t as clear. So, instead, I’m combining from a few different sources and presenting an unordered list of some of the site’s most popular content. Here you go:

    I’m really pleased with the mix of topics this year; many of these topics are straight from research papers, and others are artists’ works. At least one is both. From swimming bacteria to star-birthing nebulas, fluid dynamics are everywhere!

    If you enjoy FYFD, please remember that it’s a reader-supported website. I don’t run ads and it’s been years since my last sponsored post. You can help support the site by becoming a patron, making a one-time donation, buying some merch, or simply by sharing on social media. And if you find yourself struggling to remember to check the website, remember you can get FYFD in your inbox every two weeks with our newsletter. Happy New Year!

    (Image credits: sphinx – S. Boury et al., ear model – S. Kim et al., maze – S. Mould, dandelion – S. Chaudhry, water tank – P. Ammon, e. coli – R. Ran et al., drop impact – R. Sharma et al., Leidenfrost – L. Gledhill, toilet – J. Crimaldi et al., engine sim – N. Wimer et al., rivers – D. Coe, fin – F. Weston, snake – P. Schmid, nebula – J. Drudis and C. Sasse, flames – C. Almarcha et al.)

  • Featured Video Play Icon

    The Hydrodynamics of Marbling

    In marbling, an artist floats paints on a viscosified water bath, using various thin tools to manipulate the final image. Many cultures have developed a version of this art, but for many it will be most recognizable as a technique used to decorate book interiors. In this video, researchers consider the physics behind this beautiful practice. Surface tension helps keep the paint on the surface, even though it’s denser than the water it’s on. Variations in surface tension shape and reshape the surface as new colors are added. And then low-Reynolds-number effects help artists mix the paints without inertia or diffusion disturbing the pattern. See more examples here, here, and here. (Video credit: Y. Sun et al.)

  • Flipping Ice

    Flipping Ice

    In nature ice is ever-changing — growing, shrinking, and shifting. This poster illustrates that with a cylinder of ice floating in room temperature water. As the ice melts, it flips over into a new orientation, stays that way for a time, and then shifts again, as seen in the series of blue images. This flipping results from the melting flows around the ice, illustrated in the colorful central photo. This color schlieren image shows dense plumes of cold meltwater sinking beneath the ice. As that cold water drips down the sides of the ice, it leaves behind a wavy, patterned surface. Eventually, melting from the bottom of the ice leaves the remaining ice top-heavy, which triggers a flip into a more stable orientation. (Image and research credit: B. Johnson et al.)

  • Exoplanet Heating

    Exoplanet Heating

    WASP-96B is a tidally-locked exoplanet between the size of Saturn and Jupiter. This hot, massive planet lies close to its star, orbiting in less than three-and-a-half Earth days. A recent study shows that planets like these can have very different weather, depending on what depth their atmosphere absorbs heat at.

    Using numerical simulations, researchers took a detailed look at the possible atmospheric dynamics on this planet. When the atmosphere absorbed heat at a shallow depth — near the outer layers of the planet — a coupled vortex pair formed (left, below). These vortices promenaded westward and completed a circuit around the planet every 11-15 days.

    Shallow heating on a hot Jupiter produces a pair of coupled vortices (left), but deeper heating in the atmosphere generates four more-chaotic vortices (right).
    Shallow heating on a hot Jupiter produces a pair of coupled vortices (left), but deeper heating in the atmosphere generates four more-chaotic vortices (right).

    In contrast, deeper heating produced a more-chaotic pattern of four vortices (right, above) that each lasted 3 to 15 days before disappearing, replaced by a new vortex. This atmosphere, they found, was very turbulent, with smaller-scale vortices as well.

    Since each weather pattern is visually distinct and carries its own brightness signature, the authors predict that additional observations of WASP-96b with the current generation of telescopes will show which type of heating dominates on the exoplanet. (Image and research credit: J. Skinner et al.; via APS Physics)

    Snapshots from a simulation of a deep-heated hot Jupiter. Each image shows the planet on a different day.
    Snapshots from a simulation of a deep-heated hot Jupiter. Each image shows the planet on a different consecutive day.
  • Featured Video Play Icon

    Can Explosions Deflect Bullets?

    In one of their most Mythbusters-like videos ever, the Slow Mo Guys ask: can an explosion deflect a bullet? To find out, they built out a system to trigger a C4 explosive using a 9mm bullet, all while watching with a series of high-speed cameras. As you’d expect, there are lots of blast waves and neat flame propagation to watch. As for the fundamental question, well, you’ll have to watch to find out! (Video and image credit: The Slow Mo Guys)

  • Swarm of Surfers

    Swarm of Surfers

    Self-propelled objects can form fascinating patterns. Here, researchers investigate how small plastic “surfers” move on a vibrating fluid. Each surfer is heavier in its stern than its bow. When the fluid vibrates, the surfer creates waves that are asymmetric — deeper in the stern than at the bow. For single surfers, this imbalance propels the surfer in the direction of its bow. But with more than one surfer, other patterns form.

    The video demonstrates five of the seven patterns pairs of surfers exhibit.
    The video demonstrates five of the seven patterns pairs of surfers exhibit.

    The team looked at groups of surfers all the way up to eight members. Among pairs, the researchers found seven distinctive patterns, including orbiting groups, tailgaters, and promenading pairs. Larger groups, they found, had similar collective behaviors. They hope their surfers will be an easily accessible platform for exploring active matter. (Image and research credit: I. Ho et al.; via APS Physics)

  • “The Reef”

    “The Reef”

    Artist Alberto Seveso returns to his colorful ink plumes (1, 2, 3, 4, 5), but this time with a twist. Here, Seveso took ink injected in water and digitally altered it, adding texture and shaping the ink to mimic the shapes of coral reefs. The results are stunning, though I confess a few of them remind me of mushrooms or organs more than reefs. (Image credit: A. Seveso; via Colossal)

  • Droplet Medusa

    Droplet Medusa

    Vibration is one method for breaking a drop into smaller droplets, a process known as atomization. Here, researchers simulate this break-up process for a drop in microgravity. Waves crisscrossing the surface create localized craters and jets, making the drop resemble the Greek mythological figure of Medusa. With enough vibrational amplitude, the jets stretch to point of breaking, releasing daughter droplets. (Image and research credit: D. Panda et al.)

  • Controlling Finger Formation

    Controlling Finger Formation

    When gas is injected into thin, liquid-filled gaps, the liquid-gas interface can destabilize, forming distinctive finger-like shapes. In laboratories, this mechanism is typically investigated in the gap between two transparent plates, a setup known as a Hele-Shaw cell. In the past, researchers looking to control the instability have explored how surface tension, viscosity, and the elasticity of the gap itself affect the flows. But a new set of studies look at the compressibility of the gas being injected.

    The team found that viscous fingers formed later the higher the gas’s compressibility. That provides a potential control knob for people trying to exploit the mechanism, especially geologists. For geologists trying to extract oil, viscous fingering is detrimental, but, on the flip side, viscous fingers are desirable when injecting carbon dioxide for sequestration. With these results, users can tweak their injection characteristics to match their goals. (Image credit: C. Cuttle et al.; research credit: C. Cuttle et al. and L. Morrow et al.; via APS Physics)

  • Ciliary Pathlines

    Ciliary Pathlines

    For tiny creatures, swimming through water requires techniques very different than ours. Many, like this sea urchin larva, use hair-like cilia that they beat to push fluid near their bodies. The flows generated this way are beautiful and complex, as shown above. Importantly for the larva, the flows are asymmetric; that’s critical at these scales since any symmetric back-and-forth motion will keep the larva stuck in place. (Image credit: B. Shrestha et al.)