# gst: how to create a helix from a straight rod, “twist” or “bend” approaches.

<< There are two independent ways of creating a helix from a straight rod: curl the rod into a circle and then twist the rod all along its length to convert the ring into a helix (“twist” method), or deform the rod into a sine wave and then bend it with a sinusoidal distortion that curls at right angles to the first sine wave (“bend” method). Both procedures produce the same shape, but they generate different internal stresses within the rod, and their implementations require different amounts of energy. >>️

AA << say that their experiments could serve as a model for many physical systems that undergo handedness transitions, including the tendrils of plants, the flagella of microorganisms, and the strands of DNA molecules.  >>

️

David Ehrenstein. Two Experimental Observations of Helix Reversals. Physics 16, s158. Oct 24, 2023.  

https://link.aps.org/doi/10.1103/Physics.16.s158

Paul M. Ryan, Joshua W. Shaevitz,  Charles W. Wolgemuth. Bend or Twist? What Plectonemes Reveal about the Mysterious Motility of Spiroplasma. Phys. Rev. Lett. 131, 178401. Oct 24, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.178401

Emilien Dilly, Sebastien Neukirch, Julien Derr, Drazen Zanchi. Traveling Perversion as Constant Torque Actuator. Phys. Rev. Lett. 131, 177201. Oct 24, 2023. 

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.177201

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

Keywords: gst, elastic, elastic deformation, swimming

# gst: nano entities that are both twisted and untwisted at the same time

<< Scientists who study the nanoscale-with molecules and materials 10,000 smaller than a pinhead-need to be able to test the way that some molecules twist, known as their chirality, because mirror image molecules with the same structure can have very different properties. >>

<< Recently, a new class of nanoscale materials have been developed to help distinguish the chirality of molecules. These so-called 'nanomaterials' usually consist of tiny twisted metal wires, that are chiral themselves. However, it has become very hard to distinguish the twist of the nanomaterials from the twist of the molecules they are supposed to help study. >>

To solve this problem AA << created a nanomaterial that is both twisted and it is not. This nanomaterial has equal number of opposite twists—meaning they cancel each other out.  >>

<< Using a mathematical analysis of the material's symmetry properties, the team discovered a few special cases, which can bring the 'hidden' twist to light and allow very sensitive detection of chirality in molecules. >>

Chris Melvin. Scientists create a nanomaterial that is both twisted and untwisted at the same time. University of Bath. Sep 13, 2019   https://m.phys.org/news/2019-09-scientists-nanomaterial-untwisted.html  

Christian Kuppe,  Xuezhi Zheng, et al. Measuring optical activity in the far-field from a racemic nanomaterial: diffraction spectroscopy from plasmonic nanogratings. Nanoscale Horizons.  Issue 5, 2019.  doi: 10.1039/C9NH00067D.   https://pubs.rsc.org/en/content/articlelanding/2019/NH/C9NH00067D

# gst: apropos of degeneration, the topological degeneracy induced by twisting.

<< In recent years, twisting has emerged as a new degree of freedom that plays an increasingly important role in Bloch bands of various physical systems. However, there is currently a lack of reports on the nontrivial physics of topological degeneracy in twisted systems. >>

AA << investigated the intrinsic physical correlation between twisting and topological degeneracy. (They) found that twisting not only breaks the symmetry of the system but also introduces topological degeneracy that does not exist under the original symmetric system without twisting. >>

<< Furthermore, the topological degeneracy can be easily tuned through twisting. This new twist-induced topological degeneracy gives rise to a unique polarization-degenerate birefringent medium, wherein the twist angle acts as a novel degree of freedom for dispersion and polarization management of interface states. >> 

<< Exhibiting fascinating properties and experimental feasibilities, (AA) Letter points to new possibilities in the research of various topological physics in twisted photonics. >>️

Han Peng, Qiang Wang, et al. Topological degeneracy induced by twisting. Phys. Rev. Lett. 134, 106601. Mar 11, 2025.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.106601   arXiv: 2503.09048v1 [physics.optics]. https://arxiv.org/abs/2503.09048  

Also: degeneration, in FonT https://flashontrack.blogspot.com/search?q=degeneration   twisting, twist, in FonT   https://flashontrack.blogspot.com/search?q=twisting    https://flashontrack.blogspot.com/search?q=twist 

Keywords: gst, degeneration, twisting 

# evol: spontaneous, immediate asymmetry, the chiral twist

<< When holding a right hand in front of a mirror, one can see a reflected image of a left hand and vice versa. In 1848, Louis Pasteur discovered that organic molecules are much like our hands: they come in mirror-image pairs of left- and right-handed variants. Nowadays, we know that this handedness or chirality (from the Greek word for "hand") is a hallmark of organic molecules. >>

<< Organic molecules are rich in carbon atoms, which form bonds to create either a right or a left "nano-hand." Yet, puzzlingly, life almost always selects to exclusively use one of the two mirror-image twins—a phenomenon called homochirality. For example, terrestrial life is based on left-handed amino acids and right-handed sugars. >>️️

<< A model now proposes a novel explanation for the emergence of homochirality in life—a longstanding puzzle about the origin of life on Earth. >>️

<< Homochirality emerges spontaneously in prebiotic chemical networks that adapt to optimize energy harvesting from the environment. Previously, it was believed that chiral symmetry breaking requires multiple loops of auto-catalysis, which increasingly produces one enantiomer of a molecule while inhibiting the formation of the other. However, the IBS team's results showed that the underlying mechanism of symmetry breaking is very general, as it can occur in large reaction systems with many random molecules and does not require sophisticated network architectures. It was found that this sharp transition to homochirality stems from the self-configuration of the reaction network in order to achieve more efficient harvesting of energy from the environment. >>️

Learning chemical networks give life a chiral twist. Institute for Basic Science. Apr 26, 2022. 

https://phys.org/news/2022-04-chemical-networks-life-chiral.html

William D. Pineros, Tsvi Tlusty. Spontaneous chiral symmetry breaking in a random driven chemical system. Nat Commun 13, 2244. doi: 10.1038/ s41467-022-29952-8. Apr 26, 2022.

https://www.nature.com/articles/s41467-022-29952-8

Also

keyword 'chiral' in FonT

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

keyword 'self-assembly' in FonT

https://flashontrack.blogspot.com/search?q=self-assembly

Keywords: evolution, gst, randomness, self-assembly, self-configuration, break symmetry, asymmetry, chiral, chirality  

# rmx-s-gst: inner dances: to get a sense ...

<< To get a sense for supercoiled DNA,  imagine twisting a piece of string. Let the string go, and it unwinds. Twist it enough, and it folds back on itself. The degree of twist puts stress on the string, which governs the shape it takes >>

http://www.scientificamerican.com/article/how-strange-twists-in-dna-orchestrate-life/

Rossitza N. Irobalieva, Jonathan M. Fogg, et al. Structural diversity of supercoiled DNA. Nature Communications 6, Article number: 8440 doi:10.1038/ncomms9440

http://www.nature.com/ncomms/2015/151012/ncomms9440/full/ncomms9440.html

# gst: a concrete image, chirality by dissipation, 'this effect actually owes its existence to dissipation'

<< Normally, dissipation alters or weakens existing quantum effects-but here we have an effect that actually owes its existence to dissipation, >>  Tilman Esslinger

<< "No scientist thinks in formulae," Albert Einstein allegedly once told his colleague Leopold Infeld. In fact, especially for physicists, who deal with such abstract things as quantum physics, it is often immensely useful to work with concrete images rather than mathematical symbols. >>

Oliver Morsch. Unexpected twist in a quantum system. ETH Zurich.  Jan 10, 2020.

https://m.phys.org/news/2020-01-unexpected-quantum.html

Nishant Dogra, Manuele Landini, et al.  Dissipation-induced structural instability and chiral dynamics in a quantum gas.  Science  20 Dec 2019:

Vol. 366, Issue 6472, pp. 1496-1499

DOI: 10.1126/science.aaw4465

https://science.sciencemag.org/content/366/6472/1496   

# s-behav: the regular chaotic of wild flamingos (Phoenicopterus roseus) dancers

<< Flamingos are very good dancers. They twist and preen, they scratch their heads, they march in unison. >>

Nicholas Bakalar. Flamingo Mating Rules:  1.  Learn  the  Funky Chicken. Nov. 28,  2016.

http://mobile.nytimes.com/2016/11/28/science/flamingos-dancing-sexual-display.html

Charlotte  Perrot, Arnaud  Bechet, et al. Sexual display complexity  varies non-linearly with age and  predicts breeding  status  in  greater  flamingos.  Nature. Scientific Reports 6 (2016); Article  number:  36242. doi: 10.1038/srep36242

http://www.nature.com/articles/srep36242

# gst: deep, super-resolution vistas through tiny tornadoes of magnetized plasma

<< To get the extremely high-resolution images vital to study new materials, microbes, and more, scientists often build microscopes based on optical vortices. >>

AA << devised a way to make optical vortices with 1000 times more power than previous methods. Their design uses strong, nonuniform magnetic fields to control plasmas, or ionized gases, to create the vortices. >>

US Department of Energy. Magnetized plasmas that twist light can produce powerful microscopes and more. May 7, 2018.

https://m.phys.org/news/2018-05-magnetized-plasmas-powerful-microscopes.html

Kenan Qu, Qing Jia, Nathaniel J. Fisch. Plasma q-plate for generation and manipulation of intense optical vortices. Phys. Rev. E 96, 053207.  doi: 10.1103/PhysRevE.96.053207. Nov 28, 2017.

https://journals.aps.org/pre/abstract/10.1103/PhysRevE.96.053207

# gst: pensive billiards

AA << define a new class of plane billiards - the `pensive billiard' - in which the billiard ball travels along the boundary for some distance depending on the incidence angle before reflecting, while preserving the billiard rule of equality of the angles of incidence and reflection. This generalizes so called `puck billiards' (..), as well as a `vortex billiard', i.e. the motion of a point vortex dipole in 2D hydrodynamics on domains with boundary. (AA) prove the variational origin and invariance of a symplectic structure for pensive billiards, as well as study their properties including conditions for a twist map, the existence of periodic orbits, etc. (AA) also demonstrate the appearance of both the golden and silver ratios in the corresponding hydrodynamical vortex setting. Finally, (AA) introduce and describe basic properties of pensive outer billiards. >>

Theodore D. Drivas, Daniil Glukhovskiy, Boris Khesin. Pensive billiards, point vortices, and pucks. arXiv: 2408.03279v1 [math.DS]. Aug 6, 2024.

https://arxiv.org/abs/2408.03279

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

FonT: 'pensive billiard' evokes images in me that could inspire a series of quasi-stochastic short poems ( https://inkpi.blogspot.com ), but (for now) I will abstain.

Keywords: gst, billiards, pensive billiard, puck billiard, vortex billiard

# ai: self-programming machines with twists, the beginning

<< Researchers have developed a flexible way of combining deep learning and symbolic reasoning to teach computers to write short computer programs. >>

<< A new program-writing AI, SketchAdapt, offers a way out. Trained on tens of thousands of program examples, SketchAdapt learns how to compose short, high-level programs, while letting a second set of algorithms find the right sub-programs to fill in the details. Unlike similar approaches for automated program-writing, SketchAdapt knows when to switch from statistical pattern-matching to a less efficient, but more versatile, symbolic reasoning mode to fill in the gaps. >>

<< Rather than rely on experts to define program structure, SketchAdapt figures it out using deep learning. The researchers also added a twist: When the neural networks are unsure of what code to place where, SketchAdapt is programmed to leave the spot blank for search algorithms to fill. >>

Kim Martineau. Toward artificial intelligence that learns to write code.
MIT. June17, 2019.

https://m.techxplore.com/news/2019-06-artificial-intelligence-code.html   

Maxwell Nye, Luke Hewitt, et al. Learning to Infer Program Sketches.
arXiv:1902.06349v2 [cs.AI] Jun 4, 2019.

https://arxiv.org/abs/1902.06349 

# math: squeezing Moebius strips using either 'tame' or 'wild' embeddings, but only with overlaps

<< In math, three-dimensional space sprawls out to infinity in every direction. With an infinite amount of room, it should be able to hold an infinite number of things inside of it - pearls, peacocks or even planets. >>

<< But a recent proof (..), shows that one relatively well-known mathematical object can’t be packed an uncountably infinite number of times into an infinite amount of space: the Möbius band, a two-dimensional loop with a half-twist. >>

<< "Tame" embeddings extend to the entire space, so it’s possible to stretch or squish the space to make the embedded sphere into a standard round sphere. >>

<< "Wild" embeddings, on the other hand, are not so easily visualized and generally require some infinite process to describe. With a wild embedding, there is no way to transform the space to make the wildly embedded version a round sphere. >>

Evelyn Lamb. Möbius Strips Defy a Link With Infinity. Feb 20, 2019.

https://www.quantamagazine.org/mobius-strips-defy-a-link-with-infinity-20190220

https://twitter.com/QuantaMagazine/status/1126601994494455809

Olga D. Frolkina. Pairwise disjoint Moebius bands in space. Journal of Knot Theory and Its Ramifications. Vol. 27, No. 09, 1842005 (2018). doi: 10.1142/S0218216518420051

https://www.worldscientific.com/doi/abs/10.1142/S0218216518420051

# jazz: Zakir Hussain (tabla), Niladri Kumar (sitar). Krannert Center for the Performing Arts, Urbana, IL, USA. Nov 16, 2022.

<< Classical Indian music and jazz have much in common, Hussain (Zakir Hussain) said. Classical Indian music “encourages spontaneity and onstage twists. You try to tell the age-old story with a new twist, with a new drama, a new exclamation mark,” (..) “Jazz allows you the ability to interact as an individual, taking a piece of music and creating your vision of it. You’re training to be spontaneously creative. Indian music is the same way. That’s why you see so many Indian musicians collaborating with so many jazz musicians from all over the world,” Hussain said. His father (Ustad Alla Rakha) recorded one of the first fusion records with Indian and jazz drummers. >>️

Jodi Heckel. Tabla virtuoso Zakir Hussain, renowned sitar player Niladri Kumar performing at Krannert Center. Univ of Illinois. Nov 10, 2022. 

https://blogs.illinois.edu/view/6367/788544307

ZAKIR HUSSAIN, TABLA AND NILADRI KUMAR, SITAR. 

https://krannertcenter.com/events/zakir-hussain-tabla-and-niladri-kumar-sitar

Also 

Zakir Hussain & Niladri Kumar

https://youtu.be/zVYZ0sdnPE8

John Mclaughlin, U Srinivas, Zakir Hussain, V Selvaganesh, Mahadevan - Jazz a Vienne. The 5 Peace band - John McLaughlin (guitar), U Srinivas (Mandolin), Zakir Hussain (Tabla), V Selvaganesh (Ghatam), S Mahadevan (Vocals) perform live in Vienna. Note: This is the remember shakti lineup + S Mahadevan. The songs they play are: Caruna, Ma No Pa, Sakhi, and Giriras Sudha. May 3, 2012. 

https://youtu.be/VA7Mzo73cd4

Also

keyword 'jazz' in Notes 

(quasi-stochastic poetry)

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

keyword 'jazz' in FonT

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

keywords  '#jazz' | '#jazzy' in  @flashontrack  

https://twitter.com/flashontrack

Keywords: jazz, jazz fusion, indian music, sitar, tabla