Bursting an Oobleck Bubble

When soap bubbles burst, the hole grows as an expanding circle. But not every fluid bursts this same way. Here, researchers let air rise through oobleck–a fluid made from cornstarch suspended in water–to form a bubble. In time, as with all bubbles, the oobleck bubble bursts. But–in keeping with oobleck’s solid-like properties–the film tears open and fractures. As it sinks back into the liquid, it wrinkles before it slowly relaxes back into fluid form. (Video and image credit: X. Zhang et al.)

Frog Kick

A toad swims across a pond in this award-winning image from photographer Paul Hobson. The shot was actually captured from below the water, with the camera kept dry in a glass housing. Although the frog appears to be mid-leap, the light-distorting ripples around its feet hint at the flow its kick generated. It’s reminiscent of the vortices left by water striders as they move. (Image credit: P. Hobson/BWPA; via Colossal)

How does lava turn into hair-like glass?

Experiments show gas-rich molten rock can be stretched into thin filaments, like molten sugar. A new mechanism for the formation of “Pele’s hair”.

🔗 https://doi.org/10.1038/d41586-026-00766-8

#FluidDynamics #Volcanoes #Glass #Geophysics #Physics

What should fluid mechanics papers focus on today?

This editorial argues for a “physics-first” approach: beyond data and simulations, real progress comes from understanding mechanisms and scaling laws.

🔗 https://doi.org/10.1063/5.0329552

#FluidDynamics #Physics #ScientificPublishing #ResearchCulture #OpenScience

Fluid Flows Break Up Microswimmer Clumps

The field of active matter looks at the collective motion of particles and organisms–how birds flock and fish school. In systems of “dry” squirmers–those that have no hydrodynamic interactions with one another–clumps of squirmers can form with empty spaces in between them. This is known as motility-induced phase separation, or MIPS. Researchers wondered whether microswimmers in a fluid–which do produce hydrodynamic forces that can affect one another–would also show MIPS.

In a new study, researchers show, instead, that hydrodynamic interactions between swimmers will prevent (or destroy) these clumps. Through a combination of theoretical work and simulation, the authors found that translational flows between swimmers swept the swimmers out of clumps as they formed. Rotational flows between swimmers made them able to change direction faster, which also kept stable clumps from forming. (Image and research credit: T. Zhou and J. Brady; via APS)

If the #LeidenfrostEffect fascinates you as much as it does us, we highly recommend reading this review by Seán M. Stewart.

🔗 https://doi.org/10.1088/1361-6404/ac3fed

Beyond a simple overview, this article traces the scientific history of the phenomenon, while providing a rich and detailed perspective on the dynamics of Leidenfrost droplets.

Enjoy the read!

#fluiddynamics #heattransfer #physics #HistoryOfScience

Bursting Bubbles

When air bubbles rise through a liquid, they scavenge dust, viruses, microplastics, and other impurities as they go. Once at the surface, these contaminant-covered bubbles thin and burst, generating many tiny droplets that arc through the air above. You’re likely familiar with the sight and sensation from a glass of champagne or soda.

Here, researchers have stacked two sets of sequential images to illustrate this complicated flowscape. Under the surface, a trio of photos are stacked to show bubbles rising and gathering at the surface. In the air, the researchers have stacked thirty sequential images, which together trace out the parabolic arcs of droplets sprayed by the bursting bubbles. (Image credit: J. Do and B. Wang)

Antibubbles form only under precise conditions: droplet impact must trap air and generate a secondary jet droplet.

This study shows an optimal Weber number where formation peaks, balancing inertia and capillarity.

🔗 https://doi.org/10.1063/5.0316890

#FluidDynamics #InterfacialPhysics #WeberNumber #ThinFilms #Antibubbles

AI can now forecast turbulent flows from just a few observations, capturing tiny swirls and complex patterns in 3D. Fast predictions, low computing cost, near-real-time insights!

🔗
https://www.nature.com/articles/s41467-026-70145-4

#Turbulence #FluidDynamics #MachineLearning #FlowReconstruction #Physics