# gst: the way bubbles gallop.

<< ️Bubbles are more than fleeting pockets of air trapped in liquid: they exhibit an ever-expanding repertoire of intriguing behaviors. From da Vinci's sketches of their swirling paths to modern-day studies of their erratic dances under acoustic waves, the rich dynamics of bubbles have long captured the attention of everyday observers, engineers, and scientists alike. When exposed to periodic sound waves, bubbles can shift from regular pulsations to rapid zigzagging, mimicking the randomness of Brownian motion. Under sudden pressure changes, they may collapse violently, producing cavitation—intense shock waves capable of damaging solid surfaces. In extreme cases, the implosion may become so intense that the bubble emits a spark of light. >>

<< ️Bubbles can also challenge common intuition: they may appear to violate Archimedes' principle, sinking against gravity in oscillating fluids, and carbonated drinks. Despite centuries of explorations, new and often surprising bubble phenomena continue to emerge. One such example is the recently discovered “galloping” bubble, introduced in (AA) recent publication. Here, (They) showcase this new mechanism of bubble locomotion, highlighting its rich dynamics and striking visual appeal. >>

Jian H. Guan, Saiful I. Tamim, Connor W. Magoon, et al. The way bubbles gallop. Phys. Rev. Fluids 10, 110507. Nov 20, 2025.

https://journals.aps.org/prfluids/abstract/10.1103/fbdh-fnzv

Gallery of Fluid Motion. https://doi.org/10.1103/APS.DFD.2024.GFM.V2684816

Also: bubble, drop, droplet, droploid, instability, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubble, galloping bubbles, galloping threshold, galloping motion, galloping mechanism, instability, galloping instability, drops, droplets, droploids, transitions.

# gst: why and when merging surface nanobubbles jump.

<< Gas bubble accumulation on substrates reduces the efficiency of many physicochemical processes, such as water electrolysis. For microbubbles, where buoyancy is negligible, coalescence-induced jumping driven by the release of surface energy provides an efficient pathway for their early detachment. >>

<< At the nanoscale, however, gas compressibility breaks volume conservation during coalescence, suppressing surface energy release and seemingly disabling this detachment route. >>

<< Using molecular dynamics simulations, continuum numerical simulations, and theoretical analysis, (AA) show that surface nanobubbles with sufficiently large contact angles can nevertheless detach after coalescence. In this regime, detachment is powered by the release of pressure energy associated with nanobubble volume expansion. This (AA) finding thus establishes a unified driving mechanism for coalescence-induced bubble detachment across all length scales. >>

Yixin Zhang, Xiangyu Zhang, Detlef Lohse. Why and when merging surface nanobubbles jump. arXiv: 2509.22934v1 [cond-mat.soft]. Sep 26, 2025.

https://arxiv.org/abs/2509.22934

Also: bubble, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubbles, surface nanobubbles, surface energy release, coalescence, coalescence-induced jumping, coalescence-induced bubble detachment.

# gst: role of evaporation in stability of foam films and foams.

<< ️Understanding the stability of foam films and foams remains a challenge, despite the considerable efforts provided by the scientific community to refine their physical descriptions. This persistent difficulty underscores the interplay of various complex factors. Recently, the role of evaporation has attracted attention for its dual impact: it can either enhance stability or accelerate bursting. >>

<< ️To depict a comprehensive overview on soapy objects, (AA) propose first a short description on the evaporation of drops to present some key results on the evaporation-induced cooling and the consequences on the internal flows generated by Marangoni effects. Then, (They) review the literature on foam films and foams, examining three distinct systems: pure liquids, nonvolatile, and volatile surface active molecules. ️(AA) show that evaporation of foam films and foams can lead to significant variations of temperature. In conclusion, (They) identify a series of open questions and suggest potential research pathways to address these challenges. >>

François Boulogne, Emmanuelle Rio. Role of evaporation in stability of foam films and foams. Phys. Rev. E 112, 031001. Sep 9, 2025.

https://journals.aps.org/pre/abstract/10.1103/52dh-hnnx 

arXiv: 2509.08958v1 [cond-mat.soft]. Sep 10, 2025. 

https://arxiv.org/abs/2509.08958

Also: bubble, drop, droplet, droploid, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubbles, drops, evaporation. 

# gst: reversible switching due to attraction and repulsion: clusters, gaps, sorting, and mixing.

AA << ️describe a phase transition in continuum limits of interacting particle systems that exhibits a vertical bifurcation diagram. The transition is mediated by a competition short-range repulsion and long-range attraction. As a consequence of the transition, infinitesimal parameter variations allow switching between uniform distribution and clusters in single-species models, and between mixed and sorted states in multi-species contexts, without hysteresis. >>

Their << main technical contribution is a universal expansion for the size of vacuum bubbles that arise in this phase transition and a quantitative analysis of the effect of noise. >>

Arnd Scheel, Angela Stevens. Reversible switching due to attraction and repulsion: clusters, gaps, sorting, and mixing. arXiv: 2507.10406v1 [math.DS]. Jul 14, 2025.

https://arxiv.org/abs/2507.10406

Also: particle, bubble, noise, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, particles, bubbles, noise, short-range repulsion, long-range attraction, phase transitions.

# gst: apropos of puddles, how to design and stabilize a Leidenfrost puddle

<< Leidenfrost puddles exhibit erratic bubble bursts that release vapor trapped beneath the liquid, becoming amorphous and unstable. (AA) report a method to stabilize and design a Leidenfrost puddle. >>

<< When a thin hydrophilic layer with a suitable design is placed over the liquid, the puddle adopts the layer shape due to adhesive forces and becomes stable. (AA) show a variety of puddle designs with the required layer dimensions to avoid vapor accumulation, as well as wetting and buoyancy conditions. >>

<< With the layer, the puddle evaporation rate increases significantly and can be modified by varying the layer dimensions. Finally, an illustrative use of this method in a cooling process is presented. >>️

F. Pacheco-Vázquez, M. Aguilar-González, L. Victoria-García. Designing Leidenfrost Puddles. Phys. Rev. Lett. 133, 234001. Dec 4, 2024. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.133.234001 

Also: drop, bubble, instability, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, drops, bubbles, instability, transition

# gst: tracking four-way coupled particles in turbulence

<< In many natural and industrial applications, turbulent flows encompass some form of dispersed particles. Although this type of multiphase turbulent flow is omnipresent, its numerical modeling has proven to be a remarkably challenging problem. >>

AA << present an efficient method for point-based simulation of particles in turbulence that are four-way coupled. In contrast with traditional one-way coupled simulations, where only the effect of the fluid phase on the particle phase is modeled, this method additionally captures the back-reaction of the particle phase on the fluid phase, as well as the interactions between particles themselves. >>

AA << focus on the most challenging case of very light particles or bubbles, which show strong clustering in the high-vorticity regions of the fluid. >>

️

Xander M. de Wit, Rudie P. J. Kunnen, et al. Efficient point-based simulation of four-way coupled particles in turbulence at high number density. Phys. Rev. E 110, 015301. Jul 1, 2024. 

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.110.015301  

Also: particle, bubble, turbulence, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, particles, bubbles, turbulence

# life: the generation of multiple bubbles mediated by gerrymandering could self trapped in deadlock

AA << analysis provides an account of the vulnerabilities of collective decision-making to systematic distortion by restricted information flow. >>

The analysis << also highlights a group-level social dilemma: information gerrymandering can enable one party to sway decisions in its favour, but when multiple parties engage in gerrymandering the group loses its ability to reach consensus and remains trapped in deadlock. >>

Alexander J. Stewart, Mohsen Mosleh, et al. Information gerrymandering and undemocratic decisions. Nature. volume 573, pages 117–121 Sep 4,  2019.     https://www.nature.com/articles/s41586-019-1507-6    

Alexander J. Stewart, Joshua B. Plotkin. Here’s what happens when political bubbles collide. Sep 4, 2019.     https://theconversation.com/heres-what-happens-when-political-bubbles-collide-121856  

Also

keyword "bubble" in: FonT  https://flashontrack.blogspot.com/search?q=bubble

Also

<< dell' ombre a bolle di neurodiscoide di ghiozzo >> in: 1813b - alea in psichedelico catino.  https://inkpi.blogspot.com/2005/03/1813b-alea-in-psichedelico-catino.html

# gst: the creation of giant bubbles is underappreciated in sci res

<< In the pantheon of scientific achievement, the creation of giant soap bubbles is sadly underappreciated. >>

<< "How are such large films created, and how do they remain stable?" ask Frazier (Stephen Frazier) and co. >>

The chemistry behind how you make a record-breaking giant soap bubble.
The art of creating giant bubbles is more mysterious than it seems, but researchers are at last teasing apart the chemistry of thin soapy films. Emerging Technology from the arXiv.  Aug 24, 2019.  
https://www.technologyreview.com/s/614181/the-chemistry-behind-how-you-make-a-record-breaking-giant-soap-bubble/      

https://twitter.com/techreview/status/1166167505246871552

Stephen Frazier, Xinyi Jiang, Justin C. Burton. How to make a giant bubble.
arXiv:1908.00537v1 [physics.flu-dyn] Aug 1, 2019. 

https://arxiv.org/abs/1908.00537

FonT

a proposito di generica "creation of giant bubbles", una entita' AI, anche di "media forza", opportunamente orientata per le pulsioni sperimentali, ci giochera' alla grande, io penso ...

Anomalous formation of molecules after vapor deposition. FonT. Dec 31, 2015.   

https://flashontrack.blogspot.com/2015/12/rmx-s-gst-anomalous-formation-of.html