# gst: apropos of waves perturbed by weak turbulences

<< Wave phenomena are ubiquitous at all scales throughout the Universe, and where there are waves, there’s the potential for wave turbulence. Wave turbulence is the physical state that arises in a continuous medium when a large number of wave modes interact with each other randomly. >>

<< A specific case of wave turbulence in which weakly nonlinear waves propagate in an unbounded space is described by weak turbulence theory. Capturing the dynamics of this regime will be helpful to accurately model large fluid systems. >>

<< In a rotating fluid, the predicted wave spectrum for interacting weakly nonlinear inertial waves is perturbed by the formation of geostrophic modes—columnar vortices aligned with the rotation axis (..) (AA) successfully suppress geostrophic modes with the addition of two honeycomb-patterned plates, allowing them to confirm the predictions of weak turbulence theory. >>

Sergey Nazarenko. Verifying Weak Turbulence Theory.  Physics 13, 194. Dec 14, 2020. 

https://physics.aps.org/articles/v13/194

Eduardo Monsalve, Maxime Brunet, et al. Quantitative Experimental Observation of Weak Inertial-Wave Turbulence. Phys. Rev. Lett. 125, 254502. Dec 14, 2020.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.254502

# gst: the strong impact on nanosheets by the weak van der Waals force

<< Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls. >> 

<< Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky, (..) When you put a large, flat particle on a large, flat surface, there's a lot of contact, and it's enough to permanently deform a particle that's really thin and flexible. >> 

Matt Jones. 

<< the ubiquitous, "weak" van der Waals force was sufficient to indent a rigid silver nanosheet. The phenomenon suggests possible applications in nanoscale optics or catalytic systems. >>

<< In further experiments, (..) nanospheres could be used to control the shape of the deformation, from single ridges when two spheres are close, to saddle shapes or isolated bumps when the spheres are farther apart. >> 

Mike Williams. Weak force has strong impact on nanosheets. Rice University. Dec 15, 2020. 

https://phys.org/news/2020-12-weak-strong-impact-nanosheets.html

Sarah M. Rehn, Theodor M. Gerrard-Anderson, et al. Mechanical Reshaping of Inorganic Nanostructures with Weak Nanoscale Forces. Nano Lett. doi: 10.1021/ acs.nanolett.0c03383. Dec 10, 2020. 

https://pubs.acs.org/doi/10.1021/acs.nanolett.0c03383  

Also

keyword 'van der Waals' in FonT

https://flashontrack.blogspot.com/search?q=van+der+Waals

# behav: chaotic (jazz) music generated by songbirds during non-mating seasons for opioid reward

<< when songbirds sing during non-mating seasons, it's because singing releases an opioid naturally produced in their brain —that's right, a compound with the same biological makeup of the highly addictive painkillers. >> 

<< Animals—including birds, including humans—we produce our own endogenous opioids, and they reward behaviors naturally, like sexual behavior or feeding behavior, (..) Studies show that endogenous opioids also make play rewarding. Songbirds learn their songs, and must practice. When we listened to birds practicing in flocks, it almost sounded as if they were playing around with the notes. Darwin even suggested that birds in flocks may be singing for 'their own amusement.' So, we thought if singing is a playful behavior, it should involve opioids. >> Lauren Riters. 

<< in starlings, endogenous opioid-prompted song is evolutionarily advantageous, because singing in flocks allows them an opportunity to practice their song to prepare for the mating season. It might not be the most beautiful to listen to—Riters likened their chaotic song to freeform jazz—but that's okay. To them, it's just a warm-up for when they start looking for a mate. >> 

Songbirds sing, like humans flock, for opioid reward. University of Wisconsin-Madison. Oct 02, 2020. 

https://phys.org/news/2020-10-songbirds-humans-flock-opioid-reward.html

Stevenson, S.A., Piepenburg, A., et al. Endogenous opioids facilitate intrinsically-rewarded birdsong. Sci Rep 10, 11083. doi: 10.1038/ s41598-020-67684-1. Jul 6, 2020.

https://www.nature.com/articles/s41598-020-67684-1

# gst: complex flow patterns generated by swarms of bubbles

<< When swarms of bubbles are driven upwards through a fluid by their buoyancy, they can generate complex flow patterns in their wake. Named 'pseudo-turbulence,' these patterns are characterized by a universal mathematical relationship between the energy of flows of different sizes, and the frequency of their occurrence. This relationship has now been widely observed through 3-D simulations, but it is less clear whether it would still hold for 2-D swarms of bubbles. >>

AA << show that in 2-D simulated fluids, this pattern changes within larger-scale flows in less viscous fluids. (..) In the past, many studies of pseudo-turbulence have found the statistical properties of 3-D bubble swarms remain universal over a wide range of bubble surface tensions, fluid viscosities, and density ratios between bubbles and fluids. In 2-D fluids, however, an effect named an 'inverse energy cascade' enables energy to be transferred from small- to large-scale flows. >>

Characterising complex flows in 2-D bubble swarms. Springer. Dec 4, 2020

https://phys.org/news/2020-12-characterising-complex-d-swarms.html

Rashmi Ramadugu, Vikash Pandey, Prasad Perlekar. Pseudo-turbulence in two-dimensional buoyancy-driven bubbly flows: A DNS study. The European Physical Journal E. V 43, no. 73. doi: 10.1140/ epje/i2020-11997-0. Nov 25, 2020.

https://link.springer.com/article/10.1140/epje/i2020-11997-0

Also

keyword 'bubble' in FonT

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

# life: ten forecasts for 2021, by Saxo Bank.

(1) A successful Covid-19 vaccine kills companies.   https://www.home.saxo/content/articles/outrageous-predictions/a-successful-covid-19-vaccine-kills-companies-08122020

(2) Amazon “buys” Cyprus.   https://www.home.saxo/content/articles/outrageous-predictions/amazon-buys-cyprus-08122020

(3) Germany bails out France.   https://www.home.saxo/content/articles/outrageous-predictions/germany-bails-out-france-08122020

(4) Blockchain tech kills fake news.   https://www.home.saxo/content/articles/outrageous-predictions/blockchain-tech-kills-fake-news-08122020

(5) China’s new digital currency inspires tectonic shift in capital flows.   https://www.home.saxo/content/articles/outrageous-predictions/china-new-digital-currency-inspires-tectonic-shift-in-capital-flow-08122020

(6) Revolutionary fusion design catapults humanity into energy abundance.   https://www.home.saxo/content/articles/outrageous-predictions/revolutionary-fusion-design-catapults-humanity-into-energy-abundance-08122020 

(7) Universal basic income decimates big cities.   https://www.home.saxo/content/articles/outrageous-predictions/universal-basic-income-decimates-big-cities-08122020

(8) Disruption dividend creates Citizens Technology Fund.   https://www.home.saxo/content/articles/outrageous-predictions/disruption-dividend-creates-citizens-technology-fund-08122020

(9) Sun shines on silver, which sizzles on solar panel demand.   https://www.home.saxo/content/articles/outrageous-predictions/sun-shines-on-silver-which-sizzles-on-solar-panel-demand-08122020

(10) Next-generation tech supercharges frontier and emerging markets.   https://www.home.saxo/content/articles/outrageous-predictions/next-generation-tech-supercharges-frontier-and-emerging-markets-08122020

Pierandrea Ferrari. I 10 cigni neri del 2021. Quali sono gli eventi inaspettati che potrebbero impattare sull’economia globale nel corso del 2021? Ecco la lista stilata da Saxo Bank.  Dec 26, 2020.

https://www.money.it/I-10-cigni-neri-del-2021  

# gst: disorder can induce and modulate topological structures

 << One of the boons of topological insulators is that their conducting edge states are protected from disorder in the material’s structure. Turn up the disorder too much, however, and these topological features are usually lost. In 2018, experiments demonstrated the opposite behavior: in so-called topological Anderson insulators (TAIs), the addition of disorder can generate protected edge states, turning a trivial insulator into a topological one. Now, a team (..) reports a new type of TAI realized in a photonic crystal. Their experiments show that the crystal exhibits a wealth of topological phenomena that hadn’t been seen previously. >> 

Matteo Rini. Let Disorder Dictate Topology. Physics 13, s123. Sep 24, 2020. 

https://physics.aps.org/articles/v13/s123    

 AA << directly observe the disorder-induced topological phase transition from a trivial insulator to a TAI with robust chiral edge states. (They) also demonstrate topological heterostructures that host edge states at interfaces between domains with different disorder parameters. >> 

Gui-Geng Liu, Yihao Yang, et al. Topological Anderson Insulator in Disordered Photonic Crystals. Phys. Rev. Lett. 125, 133603. Sep 24, 2020.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.133603

# gst: structured amorphous with enforced fragmentation

<< Many substances with different chemical and physical properties, from diamonds to graphite, are made up of carbon atoms. Amorphous forms of solid carbon do not have a fixed crystal structure and consist of structural units—nanosized graphene particles. >>

(AA) << studied the structure of amorphous carbon and suggested classifying it as a separate type of amorphous solid bodies: a molecular amorphic with enforced fragmentation. (..) sp2 amorphous carbon is a fractal structure based on nanosized graphene domains that are surrounded by atoms of other elements (hydrogen, oxygen, nitrogen, sulfur, and so on). >> 

<< The discovery and experimental confirmation of the graphene nature of the 'black gold' will completely change the theory, modeling, and interpretation of experiments with this class of substances. However, some questions remain unanswered. What does solid-state physics make of this amorphous state of solid carbon? What role does amorphous carbon with sp2-hybridization play in the bigger picture?  >>  Elena Sheka.

Physicists describe a new type of amorphous solid bodies. RUDN University. Dec 03, 2020. 

https://phys.org/news/2020-12-physicists-amorphous-solid-bodies.html 

E. F. Sheka ,Ye. A. Golubev, N. A. Popova. Amorphous state of sp2 solid carbon. Fullerenes, Nanotubes and Carbon Nanostructures. doi: 10.1080/ 1536383X.2020.1815713. Sep 03, 2020.

https://www.tandfonline.com/doi/full/10.1080/1536383X.2020.1815713 

Also 

word 'allotropy' in Cambridge Dictionary

https://dictionary.cambridge.org/dictionary/english/allotropy