# gst: the role of surface tension during the collapse of a viscous bubble

<< The rupture and collapse of viscous bubbles are widespread in nature and in industrial applications. The phenomenon is accompanied by elastic sheets that develop radial wrinkles. While the weight of the film appeared to play a dominant role during film collapse and wrinkling instability, in this work, gravity appeared to play a surprisingly negligible role. Based on fluid mechanics of the phenomena, Oratis et al. showed surface tension to be the driving factor during collapse to initiate dynamic buckling instability and wrinkling behavior, accompanied with the breakdown of curved viscous and viscoelastic films. >>

Thamarasee Jeewandara. Ripple effects after slow-motion bubble collapse. Aug 17, 2020.

https://phys.org/news/2020-08-ripple-effects-slow-motion-collapse.html   

Alexandros T. Oratis, John W. M. Bush, et al. A new wrinkle on liquid sheets: Turning the mechanism of viscous bubble collapse upside down. Science. Vol. 369, Issue 6504, pp. 685-688. doi: 10.1126/ science.aba0593. Aug 7, 2020

https://science.sciencemag.org/content/369/6504/685

# gst: the sounds that occur when a soap bubble pops.

<< The popping sound of a bursting soap bubble is acquired using microphone arrays and analyzed using spherical harmonics decomposition. >>

the << acoustic emission originates mainly from the capillary stresses exerted by the liquid soap film on the air and that it quantitatively reflects the out-of-equilibrium evolution of the flowing liquid film. (..) the acoustic signature of violent events of physical or biological origin could be used to measure the forces at play during these events. >>

Adrien Bussonniere, Arnaud Antkowiak, et al. Acoustic Sensing of Forces Driving Fast Capillary Flows. Phys. Rev. Lett. 124, 084502 Feb 27, 2020.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.084502

Bob Yirka. Measuring the sound of a soap bubble popping. Phys.org. Mar 2, 2020.

https://m.phys.org/news/2020-03-soap.html

# gst: interface mobility enhances the bounce effect of bubbles

<< Theoretically, when a bubble reaches the surface of a pure liquid, the thin film of liquid between the bubble and the air above should quickly drain away, allowing the bubble to coalesce with the air. The same would be expected when two bubbles meet within the liquid or when two droplets of oil come together in water.  >>

<< Counterintuitively, bubbles or droplets reaching the highly mobile fluorocarbon liquid-air interface bounced off of the interface much more strongly than from the immobilized interface. The reason is that there is less friction on the mobile interface and thus less energy is lost during the bounce. "To our knowledge, our studies and simulations are the first to demonstrate an enhanced bounce effect due to interface mobility," >> Ivan U. Vakarelski.

When bubbles bounce back.  King Abdullah University of Science and Technology. Nov 13, 2019.

https://m.phys.org/news/2019-11-when-bubbles-bounce-back.html

Ivan U. Vakarelski, Fan Yang, et al. 

Mobile-surface bubbles and droplets coalesce faster but bounce stronger. Science Advances  25 Oct 2019:

Vol. 5, no. 10, eaaw4292 DOI: 10.1126/sciadv.aaw4292 

https://advances.sciencemag.org/content/5/10/eaaw4292

# 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

# gst: apropos of freezing bubbles ...

<< Droplets or puddles tend to freeze from the propagation of a single freeze front. In contrast, videographers have shown that as soap bubbles freeze, a plethora of growing ice crystals can swirl around in a beautiful effect visually reminiscent of a snow globe. >>

AA << characterize the physics of soap bubbles freezing on an icy substrate and reveal two distinct modes of freezing. The first mode, occurring for isothermally supercooled bubbles, generates a strong Marangoni flow that entrains ice crystals to produce the aforementioned snow globe effect. The second mode occurs when using a cold stage in a warm ambient, resulting in a bottom-up freeze front that eventually halts due to poor conduction along the bubble.  >>

S. Farzad Ahmadi, Saurabh Nath, et al. How soap bubbles freeze. Nature Communications. volume 10, Article number: 2531. Jun 18, 2019.

https://www.nature.com/articles/s41467-019-10021-6   

Rosaire Bushey. Freezing bubbles viral video inspired research now published. Virginia Tech. Jun 19, 2019.

https://m.phys.org/news/2019-06-viral-video-published.html  

# gst: apropos of bubbles, how simple foams collapse

<< When a bubble breaks, (AA) found that a collapse event propagates via impact with the receding film and tiny scattered droplets breaking other bubbles. >>

<< A key finding was that changing the viscosity of the fluid did not lead to a significant change in the number of bubbles broken. Methods to stabilize foams commonly rely on changing the viscosity, yet the team's findings clearly show how both the number of bubbles collapsed and the velocity of the receding film are unaffected. >>

Two distinct physical mechanisms identified for how simple foams collapse. Tokyo Metropolitan University. June 10, 2019.

https://m.phys.org/news/2019-06-distinct-physical-mechanisms-simple-foams.html

Naoya Yanagisawa, Rei Kurita. In-situ observation of collective bubble collapse dynamics in a quasi-two-dimensional foam. Scientific Reports 9, Article number: 5152. March 26, 2019

https://www.nature.com/articles/s41598-019-41486-6

# gst astro: when a superbubble can generate trains of shock waves

<< Sixty-seven million light-years away, a galaxy is blowing enormous bubbles. We know what they are. Known as nuclear superbubbles, the structures are likely created by the supermassive black hole in the galaxy's centre. Now, thanks to new data, we know something incredible is occurring inside them. >>

<< Observations from NASA's Chandra X-ray Observatory of spiral galaxy NGC 3079 have revealed that the bubbles are actually a huge cosmic particle accelerator, producing energetic high-speed particles around their edges.  >>

<< As the bubbles expand into the surrounding gas of the interstellar medium, they generate shock waves, which in turn produce tangled magnetic fields. (..)  particles ricochet around these shock magnetic fields; when they pass through the shock front, they get an acceleration boost.  >>

Michelle Starr. Astronomers Have Found 'Superbubbles' Producing Shock Waves in Another Galaxy.  Mar 4, 2019.

https://www.sciencealert.com/colossal-bubbles-blown-by-a-supermassive-black-hole-are-a-cosmic-particle-accelerator

Jiang-Tao Li, Edmund Hodges-Kluck, et al. Detection of non-thermal hard X-ray emission from the "Fermi bubble" in an external galaxy.  ApJ in press. arXiv:1901.10536v1 [astro-ph.HE] Jan 31, 2019.

https://arxiv.org/abs/1901.10536

# gst: images of hypothetical realities; expansion of bubbles in extra dimensions (of tiny, vibrating "string- like" entities)

<< According to string theory, all matter consists of tiny, vibrating "string-like" entities. >>

AA << proposes a new structural concept, including dark energy, for a universe that rides on an expanding bubble in an additional dimension. >>

<< The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes. >>

Our universe: An expanding bubble in an extra dimension. Uppsala University. Dec 28, 2018.

https://m.phys.org/news/2018-12-universe-extra-dimension.html

Souvik Banerjee, Ulf Danielsson, et al.  Emergent de Sitter Cosmology from Decaying Anti–de Sitter Space. Phys. Rev. Lett. 121, 261301. Dec 27, 2018.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.261301

# gst: how a bubble pops

<< After a bubble bursts at a liquid surface, the collapse of the cavity generates capillary waves, which focus on the axis of symmetry to produce a jet. >>

AA << show that the time-dependent profiles of cavity collapse (..) and jet formation (..) both obey a  inviscid scaling, which results from a balance between surface tension and inertia forces. >>

Ching-Yao Lai, Jens Eggers, and Luc Deike. Bubble Bursting: Universal Cavity and Jet Profiles. Phys. Rev. Lett. 121, 144501. Oct 2, 2018

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.144501  

John Sullivan. Math describes how bubbles pop. Princeton University. Oct 31, 2018.

https://m.phys.org/news/2018-10-math.html

# gst: a new type of vortex in the flight of a dandelion

<< Wind-dispersed plants have evolved ingenious ways to lift their seeds >>

AA << visualized the flow around dandelion seeds, uncovering an extraordinary type of vortex. This vortex is a ring of recirculating fluid, which is detached owing to the flow passing through the pappus. >>

<< The discovery of the separated vortex ring provides evidence of the existence of a new class of fluid behaviour around fluid-immersed bodies that may underlie locomotion, weight reduction and particle retention in biological and manmade structures. >>

Cathal Cummins, Madeleine Seale, et al. A separated vortex ring underlies the flight of the dandelion. Nature 2018; 562: 414–8. doi: 10.1038/s41586-018-0604-2.

https://www.nature.com/articles/s41586-018-0604-2

<< When dandelion seeds fly, a ring-shaped air bubble forms as air moves through the bristles, enhancing the drag that slows their descent. >>

Dandelion seeds reveal newly discovered form of natural flight. University of Edinburgh. Oct 17, 2018.

https://m.phys.org/news/2018-10-dandelion-seeds-reveal-newly-natural.html

# trade: positive effects of bubbles during innovations

AA << study is the first to look at the occurrence of bubbles in association with a large set of specific innovations introduced across two centuries, and to measure bubbles using statistical tests. [AA] are also the first to show that firms can benefit from bubbles driven by innovation. This is in contrast to the conventional thinking that that bubbles are detrimental that have few, if any, positive effects. >>

Ashley Kilgore. Innovation and speculation drive stock market bubble activity, according to new study. Institute for Operations Research and the Management Sciences.  Aug 1, 2018.

https://m.phys.org/news/2018-08-speculation-stock.html

<< Using a sample of 51 major innovations introduced between 1825 and 2000, [AA] test for bubbles in the stock prices of parent firms subsequent to the commercialization of these innovations. [AA] identify bubbles in 73% of the cases. >>

Alina Sorescu, Sorin M. Sorescu, et al. Two Centuries of Innovations and Stock Market Bubbles. Marketing Science 37 (4) Jul 16, 2018 doi: 10.1287/mksc.2018.1095

https://pubsonline.informs.org/doi/abs/10.1287/mksc.2018.1095

# lang: we pronounce words more slowly compared with verbs and sometimes pause

AA << study naturalistic speech from linguistically and culturally diverse populations from around the world >>

AA <<  show a robust tendency for slower speech before nouns as compared with verbs >>

Frank Seifart, Jan Strunk, et al.  Nouns slow down speech across structurally and culturally diverse languages. PNAS. doi: 10.1073/pnas.1800708115. May 14, 2018.

http://www.pnas.org/content/pnas/early/2018/05/09/1800708115/F1.large.jpg

http://www.pnas.org/content/early/2018/05/09/1800708115

<< English is peculiar (..) It can never be representative of human language in general >> Frank Seifart

<< In the years to come, as society grows more complex, the number of nouns available to us may grow exponentially. The diversity of its speakers, not so much >>

Alan Burdick. Why Nouns Slow Us Down, and Why Linguistics Might Be in a Bubble.  May 15, 2018.

https://www.newyorker.com/elements/lab-notes/why-nouns-slow-us-down-and-why-linguistics-might-be-in-a-bubble

# rmx-s-chem: a precise dance with 1 nm bubbles

<< ‘Bubble pen’ can precisely write patterns with nanoparticles as small as 1 nanometer >>

<< With this we might see the dawn of the nano machines >> (comment by  OranjeeGeneral, january 18, 2016)

http://www.kurzweilai.net/bubble-pen-can-precisely-write-patterns-with-nanoparticles-as-small-as-1-nanometer

L. Lin, X. Peng, et al.  Bubble-Pen Lithography. Nano Letters. Vol. 16: Issue. 1: Pages. 701-708. Publication Date (Web): December 17, 2015 DOI: 10.1021/acs.nanolett.5b04524

http://pubs.acs.org/doi/abs/10.1021/acs.nanolett.5b04524

# e-web-media: 'bubble effect' in information consumption

<<  people who seek out news and information from social media are at higher risk of becoming trapped in a "collective social bubble" compared to using search engines >>

http://news.indiana.edu/releases/iu/2015/12/social-media-bubbles.shtml

Dimitar Nikolov, Diego F.M. Oliveira, et al.  Measuring online social bubbles. PeerJ Computer Science, 2015; 1: e38 DOI: 10.7717/peerj-cs.38

https://peerj.com/articles/cs-38/