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1000 results for “fluiddyn”
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Sprites and ELVES
Although we are most familiar with the white, branching lightning caused by electrical discharge between clouds and the ground, there are many types of lightning. This fortuitous image captures two: tentacled red sprites and ring-like ELVES. Sprites extend upward from the top of a thunderstorm, in a large but weak flash that lasts only seconds. ELVES appear as a rapidly-expanding disc, thought to be caused by an energetic electromagnetic pulse moving into the ionosphere. They were first discovered in footage from a 1992 Space Shuttle mission. (Image credit: V. Binotto; via APOD)
#fluidDynamics #lightning #magnetohydrodynamics #meteorology #physics #plasma #science #sprite #thunderstorm -
The Best of FYFD 2025
Happy 2026! This will be a big year for me. I’ll be finishing up and turning in the manuscript for my first book — which flows between cutting edge research, scientists’ stories, and the societal impacts of fluid physics. It’s a culmination of 15 years of FYFD, rendered into narrative. I’m so excited to share it with you when it’s published in 2027.
As always, though, we’ll kick off the year with a look back at some of FYFD’s most popular posts of 2025. (You can find previous editions, too, for 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, and 2014.) Without further ado, here they are:
- Charged Drops Don’t Splash
- Strata of Starlings
- Espresso in Slow-Mo
- The Incredible Engineering of the Alhambra
- Uranus Emits More Than Thought1
- Kolmogorov Turbulence
- Bow Shock Instability
- How Particles Affect Melting Ice
- The Puquios System of Nazca
- Cooling Tower Demolition
- A Glimpse of the Solar Wind
- Bubbling Up
- A Sprite From Orbit
- Cornflower Roots Growing
- How Sunflowers Follow the Sun
What a great bunch of topics! I’m especially happy to see so many research and research-adjacent posts were popular. And a couple of history-related posts; I don’t write those too often, but I love them for showing just how wide-ranging fluid physics can be.
Interested in keeping up with FYFD in 2026? There are lots of ways to follow along so that you don’t miss a post.
And 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, 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: droplet – F. Yu et al., starlings – K. Cooper, espresso – YouTube/skunkay, fountain – Primal Space, Uranus – NASA, turbulence – C. Amores and M. Graham, capsule – A. Álvarez and A. Lozano-Duran, melting ice – S. Bootsma et al., puquios – Wikimedia, cooling towers – BBC, solar wind – NASA/APL/NRL, Lake Baikal – K. Makeeva, sprite – NASA, roots – W. van Egmond, sunflowers – Deep Look)
- I know what I did. ↩︎
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Turbulence and Bioluminescence
If you’ve ever seen crashing waves glowing blue, you’ve been treated to bioluminescence. Although many creatures can bioluminesce, tiny dinoflagellates–a type of marine phytoplankton–are one of the easiest to spot. These microscopic organisms create a flash of light in response to viscous stresses. Their response to flow-induced stresses is so robust that they can be used to visualize stress fields.
In a new study, researchers explored how turbulence affects the dinoflagellate’s luminescence. They mathematically modeled the dinoflagellate as an elastic dumbbell that emitted light based on its extent and rate of deformation. Then they explored how this model dinoflagellate behaved in different types of turbulent flows. They found that the fluctuations and intermittency of turbulent flows both encouraged the radiant displays. (Image credit: T. McKinnon; research credit: P. Kumar and J. Picardo)
#biology #bioluminescence #flowVisualization #fluidDynamics #physics #phytoplankton #science #turbulence -
Turbulence and Bioluminescence
If you’ve ever seen crashing waves glowing blue, you’ve been treated to bioluminescence. Although many creatures can bioluminesce, tiny dinoflagellates–a type of marine phytoplankton–are one of the easiest to spot. These microscopic organisms create a flash of light in response to viscous stresses. Their response to flow-induced stresses is so robust that they can be used to visualize stress fields.
In a new study, researchers explored how turbulence affects the dinoflagellate’s luminescence. They mathematically modeled the dinoflagellate as an elastic dumbbell that emitted light based on its extent and rate of deformation. Then they explored how this model dinoflagellate behaved in different types of turbulent flows. They found that the fluctuations and intermittency of turbulent flows both encouraged the radiant displays. (Image credit: T. McKinnon; research credit: P. Kumar and J. Picardo)
#biology #bioluminescence #flowVisualization #fluidDynamics #physics #phytoplankton #science #turbulence -
Turbulence and Bioluminescence
If you’ve ever seen crashing waves glowing blue, you’ve been treated to bioluminescence. Although many creatures can bioluminesce, tiny dinoflagellates–a type of marine phytoplankton–are one of the easiest to spot. These microscopic organisms create a flash of light in response to viscous stresses. Their response to flow-induced stresses is so robust that they can be used to visualize stress fields.
In a new study, researchers explored how turbulence affects the dinoflagellate’s luminescence. They mathematically modeled the dinoflagellate as an elastic dumbbell that emitted light based on its extent and rate of deformation. Then they explored how this model dinoflagellate behaved in different types of turbulent flows. They found that the fluctuations and intermittency of turbulent flows both encouraged the radiant displays. (Image credit: T. McKinnon; research credit: P. Kumar and J. Picardo)
#biology #bioluminescence #flowVisualization #fluidDynamics #physics #phytoplankton #science #turbulence -
Turbulence and Bioluminescence
If you’ve ever seen crashing waves glowing blue, you’ve been treated to bioluminescence. Although many creatures can bioluminesce, tiny dinoflagellates–a type of marine phytoplankton–are one of the easiest to spot. These microscopic organisms create a flash of light in response to viscous stresses. Their response to flow-induced stresses is so robust that they can be used to visualize stress fields.
In a new study, researchers explored how turbulence affects the dinoflagellate’s luminescence. They mathematically modeled the dinoflagellate as an elastic dumbbell that emitted light based on its extent and rate of deformation. Then they explored how this model dinoflagellate behaved in different types of turbulent flows. They found that the fluctuations and intermittency of turbulent flows both encouraged the radiant displays. (Image credit: T. McKinnon; research credit: P. Kumar and J. Picardo)
#biology #bioluminescence #flowVisualization #fluidDynamics #physics #phytoplankton #science #turbulence -
Turbulence and Bioluminescence
If you’ve ever seen crashing waves glowing blue, you’ve been treated to bioluminescence. Although many creatures can bioluminesce, tiny dinoflagellates–a type of marine phytoplankton–are one of the easiest to spot. These microscopic organisms create a flash of light in response to viscous stresses. Their response to flow-induced stresses is so robust that they can be used to visualize stress fields.
In a new study, researchers explored how turbulence affects the dinoflagellate’s luminescence. They mathematically modeled the dinoflagellate as an elastic dumbbell that emitted light based on its extent and rate of deformation. Then they explored how this model dinoflagellate behaved in different types of turbulent flows. They found that the fluctuations and intermittency of turbulent flows both encouraged the radiant displays. (Image credit: T. McKinnon; research credit: P. Kumar and J. Picardo)
#biology #bioluminescence #flowVisualization #fluidDynamics #physics #phytoplankton #science #turbulence -
Seeing Stress in an Avalanche
Researchers sometimes study avalanches and other granular flows in a rolling drum, where grains can cascade down continuously. Here, the twist is that they’ve done it with photoelastic disks, which show stress patterns when viewed under crossed polarizing filters.
In any given moment, the contacts between neighboring particles form a force chain that lights up the disks. In motion, the effect resembles lightning forking and branching across the sky. The close-ups of stress reverberating during impact are especially mesmerizing. (Video and image credit: R. Hodgson et al.)
Animation of stress reverberating through particles as they roll in a drum. #2026gosm #avalanche #flowVisualization #fluidDynamics #forceChain #granularFlow #granularMaterial #photoelastic #physics #science -
Eigentlich sollten elastische Objekte sanft in Wasser eintauchen. Wie Forscher nun aber festgestellt haben, ist das nicht immer so: Manchmal verstärkt Flexibilität den Aufprall.#Fluiddynamik #Hydrodynamik #Wasser #Bauchklatscher #Aufprall #Kraft #Mechanik #NavierStokes #Elastizität #Physik
Die Wissenschaft des besten Bauchklatschers -
A showcase of Saturn's active atmosphere! View of the #dynamics of #Saturn #atmosphere at the visible #cloud layer, from our global #climate computer #model, highlighting #JetStream (red<>blue steps) #vortices (rounded red or blue areas) #waves (oscillations from red to blue) #eddies (random red and blue fluctuations). This is a #PotentialVorticity map and this comes from our paper, see free #arxiv #PDF version https://arxiv.org/pdf/1811.01250.pdf #astro #climate #FluidDynamics #gfd #astrodon #SolarSytem
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A showcase of Saturn's active atmosphere! View of the #dynamics of #Saturn #atmosphere at the visible #cloud layer, from our global #climate computer #model, highlighting #JetStream (red<>blue steps) #vortices (rounded red or blue areas) #waves (oscillations from red to blue) #eddies (random red and blue fluctuations). This is a #PotentialVorticity map and this comes from our paper, see free #arxiv #PDF version https://arxiv.org/pdf/1811.01250.pdf #astro #climate #FluidDynamics #gfd #astrodon #SolarSytem
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A showcase of Saturn's active atmosphere! View of the #dynamics of #Saturn #atmosphere at the visible #cloud layer, from our global #climate computer #model, highlighting #JetStream (red<>blue steps) #vortices (rounded red or blue areas) #waves (oscillations from red to blue) #eddies (random red and blue fluctuations). This is a #PotentialVorticity map and this comes from our paper, see free #arxiv #PDF version https://arxiv.org/pdf/1811.01250.pdf #astro #climate #FluidDynamics #gfd #astrodon #SolarSytem
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A showcase of Saturn's active atmosphere! View of the #dynamics of #Saturn #atmosphere at the visible #cloud layer, from our global #climate computer #model, highlighting #JetStream (red<>blue steps) #vortices (rounded red or blue areas) #waves (oscillations from red to blue) #eddies (random red and blue fluctuations). This is a #PotentialVorticity map and this comes from our paper, see free #arxiv #PDF version https://arxiv.org/pdf/1811.01250.pdf #astro #climate #FluidDynamics #gfd #astrodon #SolarSytem
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A showcase of Saturn's active atmosphere! View of the #dynamics of #Saturn #atmosphere at the visible #cloud layer, from our global #climate computer #model, highlighting #JetStream (red<>blue steps) #vortices (rounded red or blue areas) #waves (oscillations from red to blue) #eddies (random red and blue fluctuations). This is a #PotentialVorticity map and this comes from our paper, see free #arxiv #PDF version https://arxiv.org/pdf/1811.01250.pdf #astro #climate #FluidDynamics #gfd #astrodon #SolarSytem
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Swimming Like a Ray
Manta rays are amazing and efficient swimmers — a necessity for any large animal that survives on tiny plankton. Researchers have built a new soft robot inspired by swimming mantas. Like its biological inspiration, the robot flaps its pectoral fins much as bird flaps its wings; this motion creates vortices that push water behind the robot, propelling it forward. For a downstroke, air inflates the robot’s body cavity, pushing the fins downward. When that air is released, its fins snap back up. With this simple and energy efficient stroke, researchers are able to control the robot’s swimming speed and depth, allowing it to maneuver around obstacles. Flapping faster helps the robot surface, and slower flapping allows it to sink. (Living manta rays also sink if they slow down.) Check out the robot in action below. (Image credit: J. Lanoy; video and research credit: H. Qing et al.; via Ars Technica)
https://www.youtube.com/watch?v=pXB9Ip7qa0o
#biology #biophysics #biorobotics #flapping #fluidDynamics #mantaRay #physics #science #swimming
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Pre-announcement of an #OpenPosition for a #lecturer in #Liphy (lab of #interdisciplinary #physics) in #Grenoble, #France
> Poste de #MCF section 28 (#Physique : Milieux denses et matériaux), sur un profil #dynamiqueDesFluides à l’échelle #nano et micro.
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A very nice Prof. who I met in Austria and GB has a PhD opening. Alidad is a cool guy and does know a lot about droplets, wetting and experiments. Here is the link to the opening: https://www.linkedin.com/feed/update/urn:li:activity:7168972914745102336/
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Growing Salty
Ngangla Ringco sits atop the Tibetan Plateau, breaking up the barren landscape with eye-catching teal and blue. This saline lake sits at an altitude of 4,700 meters, fed by rainfall, Himalayan runoff, and melting glaciers and permafrost. The lake, like many inland bodies of salt water, has no outflow. Instead, water evaporates from the lake, leaving behind any salts that were dissolved in it. Over time, those left-behind salts build up and make the lake ever saltier. (Image credit: NASA; via NASA Earth Observatory)
#astronaut #dissolution #evaporation #fluidDynamics #physics #salinity #satelliteImage #science
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Growing Salty
Ngangla Ringco sits atop the Tibetan Plateau, breaking up the barren landscape with eye-catching teal and blue. This saline lake sits at an altitude of 4,700 meters, fed by rainfall, Himalayan runoff, and melting glaciers and permafrost. The lake, like many inland bodies of salt water, has no outflow. Instead, water evaporates from the lake, leaving behind any salts that were dissolved in it. Over time, those left-behind salts build up and make the lake ever saltier. (Image credit: NASA; via NASA Earth Observatory)
#astronaut #dissolution #evaporation #fluidDynamics #physics #salinity #satelliteImage #science
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Growing Salty
Ngangla Ringco sits atop the Tibetan Plateau, breaking up the barren landscape with eye-catching teal and blue. This saline lake sits at an altitude of 4,700 meters, fed by rainfall, Himalayan runoff, and melting glaciers and permafrost. The lake, like many inland bodies of salt water, has no outflow. Instead, water evaporates from the lake, leaving behind any salts that were dissolved in it. Over time, those left-behind salts build up and make the lake ever saltier. (Image credit: NASA; via NASA Earth Observatory)
#astronaut #dissolution #evaporation #fluidDynamics #physics #salinity #satelliteImage #science
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Growing Salty
Ngangla Ringco sits atop the Tibetan Plateau, breaking up the barren landscape with eye-catching teal and blue. This saline lake sits at an altitude of 4,700 meters, fed by rainfall, Himalayan runoff, and melting glaciers and permafrost. The lake, like many inland bodies of salt water, has no outflow. Instead, water evaporates from the lake, leaving behind any salts that were dissolved in it. Over time, those left-behind salts build up and make the lake ever saltier. (Image credit: NASA; via NASA Earth Observatory)
#astronaut #dissolution #evaporation #fluidDynamics #physics #salinity #satelliteImage #science
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Ah yes, because what the world really needed was a 37x speedup in Lattice Boltzmann cylinder flow 🤦♂️. Clearly, the future of humanity hinges on reducing the cost of simulating vortex shedding 🌀 while the rest of us are just struggling to log into GitHub without existential dread. But go ahead, revolutionize fluid dynamics one cylinder at a time! 🚀
https://github.com/alikamp/Parks-KPBM-Scaling #LatticeBoltzmann #VortexShedding #FluidDynamics #TechRevolution #ExistentialDread #HackerNews #ngated -
Ah yes, because what the world really needed was a 37x speedup in Lattice Boltzmann cylinder flow 🤦♂️. Clearly, the future of humanity hinges on reducing the cost of simulating vortex shedding 🌀 while the rest of us are just struggling to log into GitHub without existential dread. But go ahead, revolutionize fluid dynamics one cylinder at a time! 🚀
https://github.com/alikamp/Parks-KPBM-Scaling #LatticeBoltzmann #VortexShedding #FluidDynamics #TechRevolution #ExistentialDread #HackerNews #ngated -
Ah yes, because what the world really needed was a 37x speedup in Lattice Boltzmann cylinder flow 🤦♂️. Clearly, the future of humanity hinges on reducing the cost of simulating vortex shedding 🌀 while the rest of us are just struggling to log into GitHub without existential dread. But go ahead, revolutionize fluid dynamics one cylinder at a time! 🚀
https://github.com/alikamp/Parks-KPBM-Scaling #LatticeBoltzmann #VortexShedding #FluidDynamics #TechRevolution #ExistentialDread #HackerNews #ngated -
Ah yes, because what the world really needed was a 37x speedup in Lattice Boltzmann cylinder flow 🤦♂️. Clearly, the future of humanity hinges on reducing the cost of simulating vortex shedding 🌀 while the rest of us are just struggling to log into GitHub without existential dread. But go ahead, revolutionize fluid dynamics one cylinder at a time! 🚀
https://github.com/alikamp/Parks-KPBM-Scaling #LatticeBoltzmann #VortexShedding #FluidDynamics #TechRevolution #ExistentialDread #HackerNews #ngated -
Ah yes, because what the world really needed was a 37x speedup in Lattice Boltzmann cylinder flow 🤦♂️. Clearly, the future of humanity hinges on reducing the cost of simulating vortex shedding 🌀 while the rest of us are just struggling to log into GitHub without existential dread. But go ahead, revolutionize fluid dynamics one cylinder at a time! 🚀
https://github.com/alikamp/Parks-KPBM-Scaling #LatticeBoltzmann #VortexShedding #FluidDynamics #TechRevolution #ExistentialDread #HackerNews #ngated -
Observing Ice Giant Atmospheres
Uranus is one of our solar system’s oddest inhabitants, stuck spinning on its side with a tilted and offset magnetosphere. To better understand it, a team observed the planet for 17 hours with JWST. The near-infrared measurements gave new insight into the planet’s ionosphere, where auroras form. They found that temperatures peaked between 3,000 and 4,000 kilometers, while ion densities peaked at 1,000 kilometers. They also confirmed previous observations that Uranus’s upper atmosphere is cooling down. (Image and video credit: ESA/Webb/NASA/CSA/STScI/P. Tiranti/H. Melin/M. Zamani; research credit: P. Tiranti et al.; via Gizmodo)
https://www.youtube.com/watch?v=3jsn1829OPw
#atmosphericScience #aurora #fluidDynamics #magnetohydrodynamics #physics #planetaryScience #science #Uranus -
Thawing Permafrost Primes Slumps
As permafrost thaws on Arctic hillsides and shorelines, the land often deforms in a unique fashion, known as a slump. Formally known as mega retrogressive thaw slumps, these areas superficially resemble a landslide. They’re also prone to repeat performances: as many as 90% of Canada’s Arctic slumps recur in the same place as previous slumps. Researchers used ground-penetrating radar and other tools to study the underground structure at slumps and found that several factors contribute to this repetitive cycle.
Seawater soaking into the foot of a hilly shore can destabilize the permafrost, creating a slump. That changes the nearby ground cover, exposing more permafrost to warming; their measurements showed this warming could extend tens of meters underground, priming the area for future slumps. Similarly, the mudslides and narrow ravines that form on an active slump also shift away ground cover and warm the underlying permafrost. Together, these factors suggest that once a slump forms, more slumps will occur as the underlying permafrost warms. (Image credit: M. Krautblatter; research credit: M. Krautblatter et al.; via Eos)
#erosion #fluidDynamics #geophysics #granularMaterial #physics #science #slump
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Thawing Permafrost Primes Slumps
As permafrost thaws on Arctic hillsides and shorelines, the land often deforms in a unique fashion, known as a slump. Formally known as mega retrogressive thaw slumps, these areas superficially resemble a landslide. They’re also prone to repeat performances: as many as 90% of Canada’s Arctic slumps recur in the same place as previous slumps. Researchers used ground-penetrating radar and other tools to study the underground structure at slumps and found that several factors contribute to this repetitive cycle.
Seawater soaking into the foot of a hilly shore can destabilize the permafrost, creating a slump. That changes the nearby ground cover, exposing more permafrost to warming; their measurements showed this warming could extend tens of meters underground, priming the area for future slumps. Similarly, the mudslides and narrow ravines that form on an active slump also shift away ground cover and warm the underlying permafrost. Together, these factors suggest that once a slump forms, more slumps will occur as the underlying permafrost warms. (Image credit: M. Krautblatter; research credit: M. Krautblatter et al.; via Eos)
#erosion #fluidDynamics #geophysics #granularMaterial #physics #science #slump
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How do fluids really slip on surfaces?
This study proposes a method to estimate slip length and reconstruct flow fields from limited data.
A key step to better understand flows where friction at the wall nearly vanishes.
#fluiddynamics #interfacialflows #SlipLength #hydrodynamics #physics