# gst: apropos of breaking mechanisms, crack of a floating particle raft caused by waves.

<< When particles of a few tens of microns are spread on the surface of water, they aggregate under the action of capillary forces and form a thin floating membrane, a particle raft. >>

<< For a sufficiently strong wave amplitude, the raft breaks up progressively by developing cracks and producing fragments whose sizes decrease on a timescale long compared to the period of the wave. (AA)  characterize the breaking mechanisms.  >>️️

<< The visual appearance of the fragments distributed in size and surrounded by open water bears a notable resemblance to the floes produced by the fracturing of sea ice by waves in the polar oceans. Fragmentation concepts and morphological tools built for sea ice floes can be applied to (AA) macroscopic analog, on which the entire dynamic evolution is accessible. However, the mechanics of the two systems differ, as (AA) particle raft breaks due to the viscous stresses, whereas the sea ice fractures due to its bending by the waves. >>️

Louis Saddier, Ambre Palotai, et al. Breaking of a floating particle raft by water waves. Phys. Rev. Fluids 9, 094302. Sep 27, 2024.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.9.094302 

Also: 'crack', 'particle', in  https://www.inkgmr.net/kwrds.html 

Also: 'break' in  https://flashontrack.blogspot.com/search?q=break

Also: 'raft' in  https://flashontrack.blogspot.com/search?q=raft

Also: 'zattera' (quasi-stochastic poetry) in  https://inkpi.blogspot.com/search?q=zattera  'randa' (quasi-stochastic poetry) in https://inkpi.blogspot.com/search?q=randa

Keywords: gst, crack, break, particle, raft, particle raft

# gst: apropos of 'normal' (jazzy?) codes, bacteria encode hidden, free-floating genes outside their genome.

AA << show that bacteria break that rule and can create free-floating and ephemeral genes, raising the possibility that similar genes exist outside of our own genome. >>️

<< What this discovery upends is the notion that the chromosome has the complete set of instructions that cells use to produce proteins, (..) We now know that, at least in bacteria, there can be other instructions not preserved in the genome that are nonetheless essential for cell survival. (..) The DNA molecule is a fully functioning, free-floating, transient gene. >> Samuel Sternberg. 

Bacteria Encode Hidden Genes Outside Their Genome—Do We? Columbia University Irving Medical Center. Aug 8, 2024. 

https://www.cuimc.columbia.edu/news/bacteria-encode-hidden-genes-outside-their-genome-do-we   

Stephen Tang, Valentin Conte, et al. De novo gene synthesis by an antiviral reverse transcriptase. Science. doi: 10.1126/ science.adq0876. Aug 8, 2024. 

https://www.science.org/doi/10.1126/science.adq0876

Also: 

codes https://flashontrack.blogspot.com/search?q=codes

DNA  https://flashontrack.blogspot.com/search?q=dna

RNA  https://flashontrack.blogspot.com/search?q=rna

CRISPR  https://flashontrack.blogspot.com/search?q=crispr

normal, jazz, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, codes, dna, rna, crispr, normal, jazz

# art: pictures of the floating world, a guide to making shadow puppets

<< Hiroshige (Utagawa Hiroshige) lived in the 19th century, the end of the classical period of ukiyo-e, the art of woodblock-printed “pictures of the floating world.” In that time he became one of the form’s last masters, having cultivated not just a high level of artistic skill but a formidable productivity. In total, Hiroshige produced more than 8,000 works. >>️

<< But his mastery encompassed more than the urban and rural landscapes of his homeland, as evidenced by this much humbler project: a set of omocha-e, or instructional pictures for children, explaining how to make shadow puppets. >>️

Hiroshige, Master of Japanese Woodblock Prints, Creates a Guide to Making Shadow Puppets for Children (1842). Art, History. Jul 6th, 2021. 

https://www.openculture.com/2021/07/hiroshige-shadow-puppets.html  

Utagawa Hiroshige. Art Institute of Chicago. 

https://www.artic.edu/artists/34946/utagawa-hiroshige

Also

keyword 'fluttuante' in Notes

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=fluttuante

keyword 'floating' in FonT

https://flashontrack.blogspot.com/search?q=floating

keyword 'onda' in Notes 

(quasi-stochastic poetry)

https://inkpi.blogspot.com/search?q=onda

keyword 'waves' in FonT

https://flashontrack.blogspot.com/search?q=waves

Keywords: arts, puppets, shadow puppets, floating worlds, waves

# gst: modeling complex nanofibril-based (cell) walls to meet diverse (bio-physical) constraints.

<< A plant cell wall's unique ability to expand without weakening or breaking -- a quality required for plant growth -- is due to the movement of its cellulose skeleton >>️

<< The new model, (..) reveals that chains of cellulose bundle together within the cell wall, providing strength, and slide against each other when the cell is stretched, providing extensibility. >>

<< The new study, (..) presents a new concept of the plant cell wall, gives insights into plant cell growth, and could provide inspiration for the design of polymeric materials with new properties. >>

<< For a long time, the prevailing concept of a plant cell wall has been that of a gel that is reinforced by cellulose fibers, with the stiff cellulose rods acting like steel rebar in cement, (..) However, we determined that cellulose chains instead stick to each other to form a network of cellulose bundles, which provides a lot more mechanical strength than disconnected rods floating in a gel. And it's the cellulose chains, rather than other components, that limit cell wall expansion, sliding alongside each other like an extension ladder when the cell is stretched. >> Daniel Cosgrove. ️

️

What makes plant cell walls both strong and extensible? Penn State. May 13, 2021. 

https://www.sciencedaily.com/releases/2021/05/210513142432.htm

Yao Zhang, Jingyi Yu, et al. Molecular insights into the complex mechanics of plant epidermal cell walls. Science. 

Vol. 372, Issue 6543, pp. 706-711

doi: 10.1126/ science.abf2824. May 14,  2021. 

https://science.sciencemag.org/content/372/6543/706

# life: the transient floating entities suspended in the skies of Venus

<< From afar, Venus seems like the most uninhabitable planet of all. >>

<< NASA’s Magellan mission conducted radar mapping of the entire surface of Venus, penetrating its cloud layer and enabling (..) to reconstruct the first 3D map of the Venusian surface. >>

<< Beneath its carbon dioxide/nitrogen atmosphere, 90 times thicker than Earth’s, a hellscape of a surface awaits. >>

<< Although (..) successfully sent numerous landers, they’ve all failed after mere hours. The reason? A layer of sulfuric acid clouds enshrouds Venus at high altitudes. These radiation-reflecting clouds create a runaway greenhouse effect: responsible for Venus’s incredible temperatures. >>

<< At 60 kilometers (36 miles) in altitude, temperatures and atmospheric pressures are similar to Earth’s. The right ingredients for life, including carbon, oxygen, and nitrogen-rich molecules, are all abundant. Ultraviolet photos of Venus display "dark patches," which Harold Morowitz and Carl Sagan suggested could indicate microorganisms. >>

<< Above the cloud-tops, Venus has been called a "paradise planet." >>

Ethan Siegel. Yes, There Really Could Be Life In The Cloud Tops Of Venus. Jul 6, 2020. 

https://www.forbes.com/sites/startswithabang/2020/07/06/yes-there-really-could-be-life-in-the-cloud-tops-of-venus/   

Also: Magellan Mission to Venus

https://nssdc.gsfc.nasa.gov/planetary/magellan.html

# gst: spontaneous spin-sliding of volatile drops

<< When a volatile solvent droplet is deposited on a freely floating swellable sheet, it can spontaneously become lobed, asymmetric, and either spin, slide or move via a combination of the two.  This process of symmetry-breaking is a consequence of the solvent droplet swelling the membrane and its inhomogeneous evaporation from the membrane, coupled with the hydrodynamics within the droplet. By tuning the membrane thickness and the droplet size, (AA) find a critical threshold that determines the transition from a quiescent spherical cap state to a self-piloted motile state.>>

Aditi Chakrabarti, Gary P. T. Choi, L. Mahadevan. Spontaneous spin-sliding of volatile drops on swelling sheets. arXiv:1910.07064v1 [cond-mat.soft]  Oct 15, 2019. 

https://arxiv.org/abs/1910.07064   

# gst: the transition from quiescent spherical cap states to self-piloted motile states of volatile droplets

<< When a volatile solvent droplet is deposited on a freely floating swellable sheet, it can spontaneously become lobed, asymmetric, and either spin, slide or move via a combination of the two. This process of symmetry-breaking is a consequence of the solvent droplet swelling the membrane and its inhomogeneous evaporation from the membrane, coupled with the hydrodynamics within the droplet. By tuning the membrane thickness and the droplet size, (AA) find a critical threshold that determines the transition from a quiescent spherical cap state to a self-piloted motile state. Simple scaling laws determine the angular and linear velocities of the droplets, and a 1D analog experiment confirms the relative roles of evaporation, swelling and viscoelastic dissipation.  >>

Aditi Chakrabarti, Gary P. T. Choi, L. Mahadevan. Spontaneous spin-sliding of volatile drops on swelling sheets. 

arXiv:1910.07064v1 [cond-mat.soft]. Oct 15, 2019

https://arxiv.org/abs/1910.07064   

Also

keyword 'droplet' in FonT  

https://flashontrack.blogspot.com/search?q=droplet

# chem: acoustic levitation techniques to perform chemistry in floating droplets

<<  Beauchamp (Jack Beauchamp) is doing work in what he calls "lab-in-a-drop" chemistry, in which chemical reactions are performed within a drop of liquid suspended in midair through acoustic levitation. >>

Performing chemistry in floating droplets. California Institute of Technology. Jul 29, 2019.

https://m.phys.org/news/2019-07-chemistry-droplets.html  

Chaonan Mu, Jie Wang, et al. Mass Spectrometric Study of Acoustically Levitated Droplets Illuminates Molecular‐Level Mechanism of Photodynamic Therapy for Cancer involving Lipid Oxidation. Angewandte Chemie International Edition. Volume 58, Issue 24. doi: 10.1002/anie.201902815. Apr 23, 2019.

https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201902815 

# gst: a floating vortex of fluff, the flight of the dandelion

<< A fluff-topped dandelion seed can float through the air for more than a kilometer before it drifts to the ground. In experiments last year, researchers revealed that the white filaments in the fluff-known collectively as a pappus-create a ring-shaped wake behind the seed that is associated with low pressure and acts to keep it aloft. >>

AA << have theoretically modeled the airflow around the pappus, reproducing the experimentally measured wake and showing that it provides the seed with steady flight capabilities. >>

Katherine Wright. Dandelion Fluff Perfected for Flight. July 2, 2019

https://physics.aps.org/synopsis-for/10.1103/PhysRevFluids.4.071901

Ledda PG, Siconolfi L, et al. Flow dynamics of a dandelion pappus: A linear stability approach. Phys. Rev. Fluids 4, 071901(R) July 2, 2019.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.4.071901

# s-astro: cosmic nomads, transfers, impacts

a) cosmic nomads

Lee Billings. Wandering in the Void, Billions of Rogue Planets without a Home. New results suggest free-floating giant planets are less common than previously believed, but hint at vast numbers of smaller castaway worlds. July 24, 2017

https://www.scientificamerican.com/article/wandering-in-the-void-billions-of-rogue-planets-without-a-home/

b) cosmic transfers

Ashley Yeager. Half of the Milky Way comes from other galaxies
Simulations suggest that galactic winds blew the material in from elsewhere. July 26, 2017

https://www.sciencenews.org/article/half-milky-way-comes-other-galaxies

Daniel Angles-Alcazar
Claude-Andre Faucher-Giguere
et al. The cosmic baryon cycle and galaxy mass assembly in the FIRE simulations. Mon Not R Astron Soc (2017) 470 (4): 4698-4719. doi: 10.1093/mnras/stx1517
Publ. June 20, 2017

https://academic.oup.com/mnras/article-abstract/doi/10.1093/mnras/stx1517/3871367/The-Cosmic-Baryon-Cycle-and-Galaxy-Mass-Assembly

c) cosmic impacts

Jenny Wells. Evidence of impacts that structured the Milky Way galaxy. July 18, 2017

https://m.phys.org/news/2017-07-evidence-impacts-milky-galaxy.html

Deborah Ferguson, Susan Gardner, Brian Yanny. Milky Way Tomography with K and M Dwarf Stars: The Vertical Structure of the Galactic Disk. The American Astronomical Society. The Astrophysical Journal, Volume 843, Number 2 . Publ. July 14, 2017.

http://iopscience.iop.org/article/10.3847/1538-4357/aa77fd/meta

# s-astro: about Milkomeda wave

<< The  two  celestial  giants  will become  one  and  stars,  planets  and  gas  clouds  will  be  hurled  into  intergalactic  space  by  titanic  gravitational  forces.  Surviving  stars  and planets  will  be  pitched  into  a  jumbled  cloud  flaring  up  with  new  stars  –  floating  into  a  long  future  not  in  the  Milky  Way,  nor Andromeda,  but  a  monstrous  “Milkomeda”  galaxy. >>

Our galaxy’s impossible collision could break gravity. 30 March 2016

https://www.newscientist.com/article/mg23030670-300-how-a-galactic-smashup-could-force-a-rethink-of-gravitys-laws/