Rheology

These Physicists Cannot Rest Until They Understand the Motions of Drunk Worms

You wake up, slightly intoxicated as tap water rinses over your body. You don’t remember why you’re here, but you’re joined by hundreds of fellow sludge worms, wriggling slowly. You start to remember: The temperature changed. The water filled with alcohol. And then the spinning begins again. While this experiment may sound odd, the scientists…

Have You Ever Seen a Soap Bubble Bounce?

Fifteen years ago, researchers used high speed video to show that when a drop of water coalesces into a layer of the same liquid, it does so not instantaneously but in a matryoshka-like cascade, with each step generating a smaller drop. Now, a newly published study finds that soap bubbles do something similar. “When gently…

Few Things Are As Captivating As Ink Billowing Through Water In Slow-Mo

The Slow Mo Guys squirted various colors of ink into a big tank of water and shot it on white seamless with a phantom 4K camera. The resulting footage, played back in suuuuuper slllllowwww moooootion, is utterly entrancing. It doesn’t take long for the ink to diffuse uniformly throughout the water. Filming it in slow…

How many licks does it take to get to the center of a Tootsie Pop? According to Jinzi Huang, co-author of a recently published study that examines how “hard candy bodies dissolve in laminar high-speed water flows,” approximately 2,500.

High-Speed Video Reveals The Source Of That Incredible After-Rain Smell

That smell has a name. It’s called petrichor. For decades, scientists have speculated on where this smell comes from, but the mechanism behind the phenomenon has remained elusive. Now, researchers at MIT studying high-speed video of raindrops think they’ve found the answer: The smell is released in tiny aerosol clouds that raindrops emit upon impact.…

There Is “Epic Movement” In A Water Drop

Directed and animated by artist Sharon Liu, Geronimo! is a whimsical, watercolor-illustrated reminder of the “epic movement we miss in every drop” of water. If you’re familiar with the fluid mechanics of water droplets, you’ll understand the reference; if you’re not, it’s high time you learned about coalescence cascades. https://gizmodo.com/high-speed-video-reveals-the-bizarre-physics-of-an-ordi-5849356 H/t The Kid Should See…

Can You Guess What This Is An Image Of?

Hint: It’s not a brain. Solution below! This image shows a cross-sectional snapshot of a simulated supermassive star going supernova, approximately one day after the star’s interior began expanding outward. The star’s helium core can be seen powering fluid instabilities and the mix of heavy elements throughout the star’s interior. This image is the work…

The Science Of Amber Waves Of Grain

Scientists have actually studied the fluid dynamics of rippling waves of wheat – like the ones referenced in the second line of “America the Beautiful ” – with experiments like the one above, in which nylon filaments imitate tall stalks of grass and soap solution the air flowing over them. FYFD’s Nicole Sharp explains: Flow…

Your New Desktop Background: Supersonic Wind Tunnel Edition

Three men (look closely) stand inside Arnold Engineering Development Complex’s 16-foot supersonic wind tunnel facility. The tunnel, seen here in 1960, is housed at Arnold Air Force Base, Tennessee, but is now inactive. Photo Credit: Phil Tarver Via FYFD: The wind tunnel was capable of Mach numbers between 1.60 and 4.75 through a test section…

Your Afternoon Catharsis: Liquid Droplets Coalescing in Slow Motion

You’ve probably seen two beads of liquid coalesce hundreds of times in your life. Maybe thousands. But we’re willing to bet you’ve never seen them do it in slow motion. This high-speed video, which was filmed at 16,000 frames per second and is played back here at 20, shows two beads of silicone oil becoming…

Behold the absolute mind-bogglery of a knuckleball in flight

MLB pitcher R.A. Dickey* slings an erratic knuckleball pitch, posing a challenge for batter and catcher alike. The ball has been colorized to highlight its almost total lack of spin, which usually serves to stabilize the ball’s trajectory. A baseball’s seams make it an imperfect sphere, which can lead to some screwy flight behavior when…

Add this to the ever-growing list of reasons ants are incredible

This video from The New York Times on the physics of fire ants is absolutely captivating. Who knew large numbers of ants could ooze, sludge-like, from a funnel, or spring back, rubber-like, when subjected to compressive forces? https://gizmodo.com/macrophotographs-of-ant-warfare-are-downright-epic-936696588 https://gizmodo.com/10-frightening-facts-you-probably-didnt-know-about-ants-5880539 Via the NYT: These images illustrated the findings of the more technical research, done with rheometers…

Tomorrow’s wind turbines could look like enormous owl wings

Engineers often take inspiration from animal designs because they’re more efficient than machines are. In the case of owl wings, nature has a major advantage over human engineering: owl wings are uncannily quiet. Now, researchers are considering outfitting wind turbines with an upscaled equivalent – if they can figure out how to do it. https://gizmodo.com/darpa-just-obliterated-the-landspeed-record-for-the-fas-5941367…

Your guide to one of the coolest physics demonstrations of all time

In this simple demonstration, we see what seems like a special effect. But it’s not. Here’s how laminar flow makes reality look like an optical illusion. Top animation adapted from a demonstration video by the UNM Physics Department It looks totally fake. Corn syrup dyed yellow, blue and red is added to a container full…

This number proves that nothing in the world is solid

One branch of science, rheology, has invented a dimensionless number. It’s called the Deborah Number, and it is meant to quantify the motto of the science: “Everything flows.” Put another way, everything in the world has liquid properties. Even mountains. Rheology was created in 1928, the collaboration of an engineer, a chemist, and a professor…

Fuck Yeah Fluid Dynamics has an awesome roundup of fluids research that’s been recognized with an Ig Nobel Prize. Past winners include a study on why coffee spills when you walk, and another on pressures involved in penguin defecation. Check out the full list at FYFD!

What do supernovae and salad dressing have in common?

Hint: The above video still shows a simulated example of the phenomenon they share. When you place a dense layer of fluid atop a less dense layer of fluid, it results in what physicists call a Rayleigh-Taylor instability. You can observe this effect in everything from salad dressing to lava lamps to evolving supernovae. Two-dimensional…

After 69 years, Earth’s slowest-moving drop has been captured on video

You guys. YOU GUYS. HOLY CRAP YOU GUYS IT FINALLY HAPPENED. After decades of observation, the climax of one of the longest running experiments in history has finally been captured on video. The pitch! It has dropped! Tar pitch is the material used to coat roofs and pave roads. If you hit it with a…

What the hell is going on with these balls?

Two glass spheres are dropped into a pool of resting water. The sphere on the left causes almost no splash at all, while the one on the right looks like it’s doing an impression of your cousin Joey pulling a cannonball at the community pool. The balls are the same size, shape and material. What…

We could watch this bouncing water droplet all. Day. Long.

And now you can, too! FYFD explains the physics behind this mesmerizing clip, which comes by way of Kahp-Yang Suh of Seoul National university in South Korea. This high-speed video shows the remarkable resilience of a water droplet upon impact against as a solid surface. The droplet deforms into a pancake-shape, with its center depressing…