FYFD

Search results for: “art”

  • The Undisturbed Waters of Lake Kivu

    The Undisturbed Waters of Lake Kivu

    Deep in Africa lies one of the world’s strangest lakes. Lake Kivu, over 450 meters in depth, is so stratified that its layers never mix. The upper portion of Lake Kivu consists of less-dense fresh water, which sits upon deeper layers of saltier water full of dissolved carbon dioxide and methane pumped into the lake by volcanic activity.

    The lake’s lack of convection means that this deep water simply stays put for thousands of years as it collects gases that remain dissolved only thanks to the immense pressure of the water above. Should that deep water be disturbed — by an earthquake, climate changes, or simply oversaturation — the resulting eruption of carbon dioxide could be deadly for the millions of people living nearby. A similar eruption at smaller Lake Nyos in 1986 asphyxiated about 1,800 people.

    Fortunately, Lake Kivu is well-monitored, so such an upwelling should not catch observers off-guard. Learn more about Lake Kivu’s oddities over at Knowable. (Image and research credit: D. Bouffard and A. Wüest, via Knowable Magazine; submitted by Kam-Yung Soh)

  • Featured Video Play Icon

    An Intro to Liquid Crystals

    There’s a good chance that the screen you’re using to read this uses liquid crystals, but how much do you know about this ubiquitous technology? Liquid crystals are fluids made up of molecules that orient into crystalline structures. Their usefulness for displays comes from the way they interact with light, changing the polarization of light based on their orientation. This Lutetium Project video is a great introduction to liquid crystals and some of their important properties, and, as always with LP videos, the journey is a beautiful one. (Image and video credit: The Lutetium Project)

    Want to learn how to promote your research in traditional media and online? This Friday Tom Crawford and I are presenting a free webinar on the topic as part of the Fluid Mechanics Webinar Series. Be sure to register ahead of time for the link and tune in at 4pm GMT (11am EST) on Friday. See you there!

  • Sensing Obstacles Through Flow

    Sensing Obstacles Through Flow

    Mosquitoes, bats, and even eels use non-visual means to sense their environments. For mosquitoes, part of their obstacle avoidance comes from the exquisite sensitivity of their antennae, which are able to sense subtle changes in the air flow around them as they approach a wall or the ground. Researchers used this same technique to help a quadcopter avoid crashing by adding air pressure sensors that respond to the changes in the copter’s wake as it approaches the ground. (Image and research credit: T. Nakata et al.; via Science)

  • Meandering

    Meandering

    The banks of rivers are in constant flux, a pattern most easily captured from above. This satellite image shows a section of the Ivalo River in Finland, swollen with snowmelt after a winter of historic snowfalls. From above we see some of the river’s previous paths. This meandering is a natural result of secondary flows where rivers bend. The water carves away sediment from the outer bank and deposits it on the inner one, exaggerating every curve until the river cuts itself off, leaving behind a sinuous lake detached from the river’s new course. For an interesting (though non-physical) look at meandering, check out this procedural system for generating maps of rivers (thanks to Kam-Yung Soh for sharing). (Image credit: J. Stevens; via NASA Earth Observatory)

  • Freezing Waves

    Freezing Waves

    Vibrate a liquid, and you’ll get a pattern of standing waves known as Faraday waves. In this project, artist Linden Gledhill adds a twist to the usual view of these waves by capturing them in plastic. As the polymer liquid vibrates, Gledhill uses a flash of UV light to cure the polymer, freezing the wave pattern. Check out the original video for an even better look. (Image, video, and submission credit: L. Gledhill, 1, 2, 3, 4)

  • Featured Video Play Icon

    Shear and Convection in Turbulence

    In nature, we often find turbulence mixed with convection, meaning that part of the flow is driven by temperature variation. Think thunderstorms, wildfires, or even the hot, desiccating winds of a desert. To better understand the physics of these phenomena, researchers simulated turbulence between two moving boundaries: one hot and one cold. This provides a combination of shear (from the opposing motion of the two boundaries) and convection (from the temperature-driven density differences).

    Please note that, despite the visual similarity, these simulations are not showing fire. There’s no actual combustion or chemistry here. Instead, the meandering orange streaks you see are simply warmer areas of turbulent flow, just as the blue ones are cooler areas. The shape and number of streaks are important, though, because they help researchers understand similar structures that occur in our planet’s atmosphere — and which might, under the wrong circumstances, help drive wildfires and other convective flows. (Image, research, and video credit: A. Blass et al.)

  • Featured Video Play Icon

    Slow Motion Speech

    Sneezing, coughing, and speaking all produce a spray of droplets capable of spreading COVID-19 and other respiratory illnesses. This Slow Mo Guys video is the latest demonstration in a long line of evidence for why wearing masks in public is such an important part of ending our current public health crisis. Also, I think we can all agree: that sneeze footage is gross. (Image and video credit: The Slow Mo Guys)

  • Hudson Bay Watercolors

    Hudson Bay Watercolors

    Rivers sweep fresh water and sediment into the Hudson Bay in this satellite image. Dark brown plumes mark the mouths of several coastal rivers as they add to the cyclonic sediment flow around the bay and out the Hudson Strait. Paler swirls, like strokes of watercolors, mark turbulent mixing between the sediment-filled shallows and the deep blue waters of the bay. (Image credit: J. Stevens/USGS; via NASA Earth Observatory)

  • Featured Video Play Icon

    “The Unseen Sea”

    San Francisco’s picturesque fogs form “The Unseen Sea” in Simon Christen’s timelapse. Viewed at the right speed, the motion of clouds becomes remarkably ocean-like, with standing waves and surges against the hillside like waves crashing on a beach. Clouds in air don’t have the same surface tension effects as water waves in air, but, for the most part, the physics of their motion is the same, which is why they look so alike. (Image and video credit: S. Christen)

  • Understanding Stars’ Seismology

    Understanding Stars’ Seismology

    Our understanding of Earth’s interior is based mostly on observations of seismic waves, which travel differently through our rocky crust and the molten core. Scientists similarly use seismic waves in stars to determine their interiors. But the pressure and temperature conditions in stars are far beyond anything we have here on Earth, which makes predicting how waves will travel in such exotic material difficult.

    To better understand these extreme temperatures and pressures, scientists are using Lawrence Livermore’s National Ignition Facility (NIF) to mimic conditions similar to the outer envelope of a white dwarf star, like the one shown in the center of the image above. NIF’s laser array – shown as the blue lines in the artist’s conception above – can generate spherical shock waves that, as they converge on a solid sample, create pressures as high as 450 Mbar, more than 400 million times sea level atmospheric pressure here on Earth. Although the shock wave takes only 9 ns to travel across the sample, it’s enough to give researchers a glimpse into star-like conditions. (Image credit: NASA/ESA/C. O’Dell/D. Thompson, Lawrence Livermore National Laboratory; via Physics Today)

More posts