Search results for: “art”

  • Featured Video Play Icon

    Engineering the City of Venice

    In 452, Roman refugees established what became the city of Venice across a series of low-lying marshy islands in a lagoon. With no solid ground available, Venice has needed clever engineering for its infrastructure, as discussed in this Primal Space video. That started with building the first piles — which still survive to this day — by driving long timbers down into harder clay levels. Because these wooden poles sit entirely below the water and are capped with stone foundations, they are preserved against rotting.

    As Venice grew over the next thousand years, its citizens had other infrastructure problems to solve. When fresh water needs outstripped what could be delivered by boat from the mainland, Venetians redesigned the substructure of each square to capture, filter, and store rainwater. And to wash away waste, they designed tunnels that use gravity and the daily tides to flush out sewage. (Video and image credit: Primal Space)

  • Beneath the Surf

    Beneath the Surf

    A surfer duck-dives beneath a passing wave in this image from photographer John Barton. I always love seeing big waves from this underwater perspective. The turbulent surf looks like storm clouds, and sometimes you see features that are invisible from the surface. Barton’s shot captures the dichotomy of serenity and chaos in the breaking surf. (Image credit: J. Barton/OPOTY; via Colossal)

  • Swirls of Green and Teal

    Swirls of Green and Teal

    Captured in March 2024, this satellite image of the Gulf of Oman comes from an instrument aboard the PACE spacecraft. The picture of a phytoplankton bloom is not quite natural-color, at least not as our eyes would see it. Instead, engineers combined data taken from multiple wavelengths and adjusted it to bring out the fine details. It’s not what we’d see by eye, but every feature you see here is real.

    Traditionally, the only way to identify the species of a phytoplankton bloom like this one is by taking a sample directly. But PACE’s instruments can detect hundreds of wavelengths of light, offering enough color detail that scientists may soon be able to identify and track phytoplankton species by satellite image alone. I wonder if distinguishing species could also provide some quantitative flow visualization from a series of these images. In the meantime, at least we can enjoy the view! (Image credit: J. Knuble; via NASA Earth Observatory)

  • Measuring Microfibers in Turbulence

    Measuring Microfibers in Turbulence

    Microplastic pollution is on the rise, especially in waterways. Microfibers — millimeters in length but only microns in diameter — are especially prevalent, as they get washed out of synthetic clothing. Collecting these pollutants first requires understanding how they move and cluster in turbulent flows. Researchers investigated that using a small water channel and high-resolution cameras.

    The team followed microfiber strands as they moved through turbulence, paying special attention to how the fibers tumbled (rotating about their short axis) and spin (rotating around their long axis). How much fibers tumbled depended on the turbulence level; with more intense turbulence, the fibers tumbled more. Rates of spinning, they found, were consistently even higher than those for tumbling. By better understanding how microfibers behave in turbulence, we’ll be able to, for example, predict how far plastics will travel before settling to the ocean floor. (Image credit: Adobe Stock Photos; research credit: V. Giurgiu et al.; via APS Physics)

  • Origins of Salt Polygons

    Origins of Salt Polygons

    Around the world, dry salt lakes are crisscrossed by thousands of meter-wide salt polygons. Although they resemble crack patterns, these structures are actually the result of convection occurring in the salty groundwater beneath the soil. I have covered the physics previously, but this new article by several of the researchers gives a behind-the-scenes glimpse of the investigation itself and how they uncovered the true explanation. (Image credit: S. Liu, see also: Physics Today)

  • Curved Rocks Hit Harder

    Curved Rocks Hit Harder

    Intuition suggests that a flat rock will hit the water with greater force than a spherical one, and experiments uphold that. But a flat rock, interestingly, doesn’t produce the greatest impact force. Instead, it’s a slightly curved rock that experiences peak impact forces. Researchers found this happens because of the thin layer of air that coats the front of the impacting object. For flat faces, this layer is relatively thick and provides a cushioning effect that reduces the peak force and spreads out the impact. In contrast, a slightly curved convex surface traps a thinner air layer, and that lack of cushioning maximizes the impact force. (Image credit: J. Wixom; research credit: J. Belden et al.; via APS Physics)

  • Featured Video Play Icon

    “Black”

    In “Black,” filmmaker Susi Sie combines her visuals of shifting ferrofluids with the music and soundscape of Clemens Haas to create an ominous, almost claustrophobic vibe. With fast cuts and shallow focus, the sharpened points of the normal-field instability appear as flashes of brightness in the dark. At times, the liquid’s surface looks almost like a speaker cone, which is appropriate since ferrofluids are frequently used in speakers to provide cooling and enhance performance. (Video and image credit: Susi Sie)

  • Resolution Effects on Ocean Circulation

    Resolution Effects on Ocean Circulation

    The Gulf Stream current carries warm, salty water from the Gulf of Mexico northeastward. In the North Atlantic, this water cools and sinks and drifts southwestward, emerging centuries later in the Southern Ocean. Known as the Atlantic Meridional Overturning Circulation (AMOC), this circulation is critical, among other things, to Europe’s temperate climate. Since 1995, scientists have been warning that human-driven climate change is weakening the AMOC and may cause it to shut down entirely — which would have catastrophic consequences for our society.

    Comparison of ocean current speeds in the low-resolution (left) and high-resolution (right) simulations.
    Comparison of ocean current speeds in the low-resolution (left) and high-resolution (right) simulations.

    A recent study re-examined the AMOC using both low- and high-resolution numerical simulations, combined with direct observations. Both simulations covered 1950 – 2100 and found the AMOC’s strength has declined since 1950. But the high-resolution simulation found significant regional variations in the AMOC’s behavior. Some regions saw localized strengthening, while other areas showed abrupt collapse. These sensitive shifts underscore the importance of driving toward higher resolutions in our next-generation climate models, if we want to better understand — and perhaps predict — what lies ahead as our climate changes. (Image credit: illustration – Atlantic Oceanographic and Meteorological Laboratory, simulations – R. Gou et al.; research credit: R. Gou et al.; via APS Physics)

  • Trapped in a Taylor Column

    Trapped in a Taylor Column

    The world’s largest iceberg, A23a, is stuck. It’s not beached; there are a thousand meters or more of water beneath it. But thanks to a quirk of the Earth’s rotation, combined with underwater topology, A23a is stuck in place, spinning slowly for the foreseeable future. A23a is trapped in what’s known as a Taylor column, a rotating column of fluid that forms above submerged objects in a rotating flow. You can see the same dynamics in a simple tabletop tank.

    Pirie Bank sticks up from the seafloor, which sets up a stationary column of rotating water that iceberg A23a is now stuck in.
    Pirie Bank sticks up from the seafloor, which sets up a stationary column of rotating water that iceberg A23a is now stuck in.

    When a tank (or planet) is rotating steadily, there’s little variation in flow with depth. With an obstacle at the deepest layer — in this case, an underwater rise known as the Pirie Bank — water cannot pass through that lowest layer. And that deflection extends to all the layers above. The water above Pirie Bank just stays there, as if the entire column is an independent object. Caught inside this region, A23a will remain imprisoned there. How long will that last? There’s no way to know for sure, but a scientific buoy in another nearby Taylor column has been hanging out there for 4 years and counting. (Image credit: A23a – D. Fox/BAS, diagram – IBSCO/NASA; via BBC News; submitted by Anne R.)

  • The Solar Corona in Detail

    The Solar Corona in Detail

    The sun’s corona — its outer atmosphere — is usually impossible to see, since it’s far outshone by the rest of the sun. But during a total solar eclipse, the moon blocks out all but the vibrant, wispy corona. Getting a detailed image of the corona is tough; it’s constantly shifting. For this image, engineer Phil Hart used 5 main cameras, 4 refractors, 2 laptops, and plenty of digital image processing to capture some incredible details of the plasma and hot gases dancing along the sun’s magnetic field lines. You can learn about the awesome effort behind this image — and see more awesome photos from the eclipse — at his site. (Image credit: P. Hart; via APOD)