# gst: exploring the on-demand dynamical generation of a plethora of dispersive shock waves arising in attractive one-dimensional droplet-bearing environment.

AA << demonstrate the controllable generation of distinct types of dispersive shock-waves emerging in a quantum droplet bearing environment with the aid of step-like initial conditions. Dispersive regularization of the ensuing hydrodynamic singularities occurs due to the competition between meanfield repulsion and attractive quantum fluctuations. This interplay delineates the dominance of defocusing (hyperbolic) and focusing (elliptic) hydrodynamic phenomena respectively being designated by real and imaginary speed of sound. >>

<< Surprisingly, dispersive shock waves persist across the hyperbolic-to-elliptic threshold, while a plethora of additional wave patterns arise, such as rarefaction waves, traveling dispersive shock waves, (anti)kinks and droplet wavetrains. >>

AA << results pave the way for unveiling a multitude of unexplored coherently propagating waveforms in such attractively interacting mixtures. >>

Sathyanarayanan Chandramouli, Simeon I. Mistakidis, Garyfallia C. Katsimiga, Panayotis G. Kevrekidis. 

Dispersive shock waves in a one-dimensional droplet-bearing environment. arXiv: 2404.02998v2 [nlin.PS]. Apr 5, 2024. 

https://arxiv.org/abs/2404.02998

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

Keywords: gst, waves, drops 

# brain: the sense of hearing, the sense of silence.

<< Do we only hear sounds? Or can we also hear silence? These questions are the subject of a centuries-old philosophical debate between two camps: the perceptual view (we literally hear silence), and the cognitive view (we only judge or infer silence). >>

<< In all cases (concerning seven experiments), silences elicited temporal distortions perfectly analogous to their sound-based counterparts, suggesting that auditory processing treats moments of silence the way it treats sounds. Silence is truly perceived, not merely inferred. >>️

️

Rui Zhe Goh, Ian B. Phillips, Chaz Firestone. The perception of silence. 

PNAS. 120 (29) e2301463120. Jul 10, 2023. 

https://www.pnas.org/doi/10.1073/pnas.2301463120

Roberto Molar Candanosa. The sound of silence? Researchers prove we can  hear it. Johns Hopkins University - HUB. Jul 11, 2023. 

https://hub.jhu.edu/2023/07/11/can-we-hear-silence 

Researchers Prove We Hear the 

Sound of Silence. Jul 10, 2023. 

https://youtu.be/nCRosndUfMc

Also: silence, pause, sound, noise, perception, brain, in https://www.inkgmr.net/kwrds.html 

Keywords:  brain, perception, sound, noise, pause, silence

# gst: even a single bubble can produce creative musical outcomes

<< Producing original and arranging existing musical outcomes is an art that takes years of learning and practice to master. Yet, despite the constant advances in the field of AI-powered musical creativity, production of quality musical outcomes remains a prerogative of the humans. Here we demonstrate that a single bubble in water can be used to produce creative musical outcomes, when it nonlinearly oscillates under an acoustic pressure signal that encodes a piece of classical music. >>️

Ivan S. Maksymov. Musical creativity enabled by nonlinear oscillations of a bubble in water. arXiv:2304.00822v1 [cs.SD]. Apr 3, 2023. 

https://arxiv.org/abs/2304.00822

keyword "bubble" in FonT

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

Keywords: gst, ai, fluid dynamics, bubble, sound, music, audio processing

# astro: eight new echoing black hole binaries (in Milky Way)

<< Scattered across our Milky Way galaxy are tens of millions of black holes—immensely strong gravitational wells of spacetime, from which infalling matter, and even light, can never escape. Black holes are dark by definition, except on the rare occasions when they feed. As a black hole pulls in gas and dust from an orbiting star, it can give off spectacular bursts of X-ray light that bounce and echo off the inspiraling gas, briefly illuminating a black hole's extreme surroundings. >>

<< In a study appearing (..) in the The Astrophysical Journal, (AA) report (..) eight new echoing black hole binaries in our galaxy. Previously, only two such systems in the Milky Way were known to emit X-ray echoes. >>️

 << Kara (Erin Kara) and her colleagues are using X-ray echoes to map a black hole's vicinity, much the way that bats use sound echoes to navigate their surroundings. (..)  As a side project, Kara is working with MIT education and music scholars, Kyle Keane and Ian Condry, to convert the emission from a typical X-ray echo into audible sound waves. >>️️

Jennifer Chu. Search reveals eight new sources of black hole echoes. MIT.  May 2, 2022. 

https://phys.org/news/2022-05-reveals-sources-black-hole-echoes.html

https://youtu.be/iIeIag2Ji8k

Jingyi Wang, Erin Kara, et al. The NICER "Reverberation Machine": A Systematic Study of Time Lags in Black Hole X-Ray Binaries. ApJ. 930, 18. May 2, 2022. 

https://iopscience.iop.org/article/10.3847/1538-4357/ac6262

Also

keyword 'black hole' in FonT

https://flashontrack.blogspot.com/search?q=black+hole

keyword 'waves' in FonT

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

keyword 'onda' in Notes 

(quasi-stochastic poetry)

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

Keywords: astro, black hole, echoes, waves

# astro: going beyond a performance by Frank Zappa (or a speech by – for example – a political entity), two speeds of sound found on Mars

AA << find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, revealing a dissipative regime extending over 5 orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), (AA) highlight two distinct values for the speed of sound that are ~10 m/s apart below and above 240 Hz, a unique characteristic of low-pressure CO2-dominated atmosphere. (They) also provide the acoustic attenuation with distance above 2 kHz, allowing to elucidate the large contribution of the CO2 vibrational relaxation in the audible range. >>

Maurice, S., Chide, B., Murdoch, N. et al. In situ recording of Mars soundscape. Nature. doi: 10.1038/ s41586-022-04679-0. Apr 1, 2022. 

https://www.nature.com/articles/s41586-022-04679-0

<< All of these factors would make it difficult for two people to have a conversation only five meters (16 feet) apart >> Sylvestre Maurice.

Juliette Collen and Daniel Lawler. First audio recorded on Mars reveals two speeds of sound. Phys.org. Apr 1, 2022. 

https://phys.org/news/2022-04-audio-mars-reveals.html

NASA Perseverance Rover Captures 

Puff, Whir, Zap Sounds from Mars 

https://youtu.be/lX5iVyfF3N0

Also

Frank Zappa 

https://www.zappa.com/

image from  

https://www.zappa.com/sites/g/files/aaj776/f/styles/suzuki_breakpoints_image_tablet_16x9/public/news/202104/Zappa88-Home-banner-03.jpg

keywords: astro, mars, acoustics, sound, speed of sound, dissipative regimes, music, jazz, freejazz

# life; apropos of mechanic (not metamechanic) convergence, a case of extreme #ctz behavior, the 'Iron Curtain'.

<< What we have heard today are not just missile blasts, fighting and the rumble of aircraft, (..) This is the sound of a new iron curtain, which has come down and is closing Russia off from the civilised world. >> Volodymyr Zelenskiy.

Luke Harding and Emma Graham-Harrison in Kyiv, Andrew Roth and Pjotr Sauer in Moscow, Julian Borger in Washington, and Sam Jones. Ukraine fighting to stop ‘a new iron curtain’ after Russian invasion. Thu 24 Feb 2022,  18:09 GMT. 

https://www.theguardian.com/world/2022/feb/24/russia-attacks-ukraine-news-vladimir-putin-zelenskiy-russian-invasion

️

Also

keyword 'ctz' entities in FonT

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

Iron Curtain. Wikipedia. Last v.: Loew Galitz. 20 Feb 2022. 

https://en.m.wikipedia.org/wiki/Iron_Curtain

keywords: life, ctz, iron curtain.

# gst: apropos of discomfort tolerances, maximize a sweet spot (of a sound zone)

AA << considered the sweet spot as the region where the a sound scene is psycho-acoustically close to a desired auditory scene. >>

They << developed a method (SWEET-ReLU algorithm) that generates a sound scene that maximizes this sweet spot while guaranteeing no discomfort over a spatial region of interest. (..) the sweet spot and the discomfort tolerance can be modeled within a flexible monaural psycho-acoustic framework. >>

Pedro Izquierdo Lehmann, Rodrigo F. Cadiz, Carlos A. Sing Long. Maximizing the Psycho-Acoustic Sweet Spot. arXiv: 2201.01461v1 [eess.AS]. Jan 5, 2022.

https://arxiv.org/abs/2201.01461

Keywords: sound, psycho-acoustics, discomfort tolerance

# brain: brain images of silence

<< When imagining music, the musicians' brain activity had the opposite electrical polarity to when they listened to it -- indicating different brain activations -- but the same type of activity as for imagery occurred in silent moments of the songs when people would have expected a note but there wasn't one. >>

<< There is no sensory input during silence and imagined music, so the neural activity we discovered is coming purely from the brain's predictions e.g., the brain's internal model of music. Even though the silent time-intervals do not have an input sound, we found consistent patterns of neural activity in those intervals, indicating that the brain reacts to both notes and silences of music. Ultimately, this underlines that music is more than a sensory experience for the brain as it engages the brain in a continuous attempt of predicting upcoming musical events. Our study has isolated the neural activity produced by that prediction process. And our results suggest that such prediction processes are at the foundation of both music listening and imagery. >> Giovanni Di Liberto. 

The music of silence: Imagining a song triggers similar brain activity to moments of mid-music silence. Trinity College Dublin. Aug 3, 2021. 

https://www.sciencedaily.com/releases/2021/08/210803105600.htm

Guilhem Marion, Giovanni M. Di Liberto,  Shihab A. Shamma. The Music of Silence. Part I: Responses to Musical Imagery Encode Melodic Expectations and Acoustics. Journal of Neuroscience  JN-RM-0183-21. doi: 10.1523/ JNEUROSCI.0183-21.2021. 2 Aug 2, 2021.

https://www.jneurosci.org/content/early/2021/07/23/JNEUROSCI.0183-21.2021.

Giovanni M. Di Liberto, Guilhem Marion,  Shihab A. Shamma. The music of silence. Part II: Music Listening Induces Imagery Responses. Journal of Neuroscience JN-RM-0184-21. doi: 10.1523/ JNEUROSCI.0184-21.2021. 

Aug 2, 2021.

https://www.jneurosci.org/content/early/2021/07/22/JNEUROSCI.0184-21.2021

Also

2123 - le dislocazioni pausali di Theo. 

(quasi-stochastic poetry). Notes. Feb 26, 2007.

https://inkpi.blogspot.com/2007/02/2123-le-dislocazioni-pausali-di-theo.html

A pause (acyclic pauses?)  approach to enhance and manage creativity. Mar 23, 2019.

https://flashontrack.blogspot.com/2019/03/brain-pause-acyclic-pauses-approach-to.html

We pronounce words more slowly compared with verbs and sometimes pause. May 20, 2018.

https://flashontrack.blogspot.com/2018/05/lang-we-pronounce-words-more-slowly.html

# gst: when and how a levitating droplet sings (as a pipe)

<< Sprinkle water onto a very hot pan, and you may notice that the droplets evaporate surprisingly slowly. They stick around because of what’s called the Leidenfrost effect—a thin layer of vapor forms between the droplets and the hot surface, insulating them from the heat, and keeping them from boiling off immediately. (..) droplets of water in this Leidenfrost regime emit periodic sounds, or beats.  >>️

<< While emitting sounds, the droplets oscillated as pulsing stars whose points moved radially in and out. (..) this vapor-layer frequency matched the period of the beats, and (AA) therefore concluded that vapor escaping from beneath the droplet was responsible for producing the periodic sounds. >>️

<< the frequency of the sounds made by a droplet depended on the droplet’s size—following the model of an organ pipe, whose tone depends on the velocity of sound and the length of the pipe. This implies that the sound production mechanism in a Leidenfrost droplet is similar to that of a wind instrument. >>

️

Erika K. Carlson. The Sounds of Levitating Water Droplets. Physics 13, s148. Nov 19, 2020.

https://physics.aps.org/articles/v13/s148

Tanu Singla,  Marco Rivera. Sounds of Leidenfrost drops. Phys. Rev. Fluids 5, 113604. doi: 10.1103/ PhysRevFluids.5.113604. Nov 19, 2020.

https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.5.113604

img     https://physics.aps.org/assets/73455c27-7d24-443b-a685-de931db74e09/e148_1.png

# life: non-human jazz from vibrant cobweb strings performed by a harp-like instrument

<< The spider lives in an environment of vibrating strings, (..) They don't see very well, so they sense their world through vibrations, which have different frequencies. (..) Such vibrations occur, for example, when the spider stretches a silk strand during construction, or when the wind or a trapped fly moves the web. (..) Webs could be a new source for musical inspiration that is very different from the usual human experience, >>️ Markus Buehler️

AA << scanned a natural spider web with a laser to capture 2D cross-sections and then used computer algorithms to reconstruct the web's 3D network. The team assigned different frequencies of sound to strands of the web, creating "notes" that they combined in patterns based on the web's 3D structure to generate melodies. The researchers then created a harp-like instrument and played the spider web music in several live performances around the world. >>️

Making music from spider webs. ACS - Am Chem Soc. Apr 12, 2021

https://phys.org/news/2021-04-music-spider-webs.html

Isabelle Su, Zhao Qin, et al. Imaging and analysis of a three-dimensional spider web architecture. J R Soc Interface. 15(146): 20180193. doi: 10.1098/ rsif.2018.0193. Sep 19, 2018. 

https://pubmed.ncbi.nlm.nih.gov/30232240/

# gst: doubling phonons by subtraction of one of them (in an optical whispering-gallery microresonator)

 << What happens now when you add or subtract a single phonon? At first thought, you may expect this would simply change the average to n + 1 or n - 1, respectively, however the actual outcome defies this intuition. Indeed, quite counterintuitively, when you subtract a single phonon, the average number of phonons actually goes up to 2n.  This surprising result where the mean number of quanta doubles has been observed for all-optical photon-subtraction experiments and is observed for the first time outside of optics here. >>

<< One way to think of the experiment is to imagine a claw machine that you often see in video arcades, except that you can't see how many toys there are inside the machine. Before you agree to play, you've been told that on average there are n toys inside but the exact number changes randomly each time you play. Then, immediately after a successful grab with the claw, the average number of toys actually goes up to 2n, >> Michael Vanner. 

Adding or subtracting single quanta of sound.  Imperial College London. Jan 25, 2021. 

https://phys.org/news/2021-01-adding-quanta.html

G. Enzian, J. J. Price, et al. Single-Phonon Addition and Subtraction to a Mechanical Thermal State. Phys. Rev. Lett. 126, 033601. Jan 21, 2021.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.126.033601

# gst: self-assembly of chemistry with music

<< audible sound can control chemical reactions in solution by continuously supplying energy sources into the interface between air and the solution.  The sound-controlled air-liquid chemical interactions 'painted' intriguing and aesthetic patterns on the surface and bulk of the solution.>>

<< The Pied Piper of Hamelin tells the mythological story of a pied piper who lured rats away from the city of Hamelin by enchanting them with the music from his magical pipe. With music working like a fuel for such artistic control in chemistry, our study has shown that even synthetic molecules can exhibit life-like behavior—listening and following a musical track, >> Rahul Dev Mukhopadhyay. 

Seeing chemical reactions with music. Institute for Basic Science. Aug 10, 2020.

https://phys.org/news/2020-08-chemical-reactions-music.html

<< the patterns obtained from artificially designed out-of-equilibrium chemical oscillating networks (such as the Belousov–Zhabotinsky reaction for example) are unpredictable and difficult to control spatiotemporally, albeit reproducible over subsequent cycles. Here, (AA) show that it is possible to generate reproducible spatiotemporal patterns in out-of-equilibrium chemical reactions and self-assembling systems in water in the presence of sound waves, which act as a guiding physical stimulus. >>

Hwang, I., Mukhopadhyay, R.D., Dhasaiyan, P. et al. Audible sound-controlled spatiotemporal patterns in out-of-equilibrium systems. Nat. Chem. 12, 808–813 (2020). doi: 10.1038/ s41557-020-0516-2. Aug 10, 2020.

https://www.nature.com/articles/s41557-020-0516-2    

# gst: controlling particles with sound waves

<< Contactless manipulation of particles and cells using sound radiation forces that can be tuned and adjusted in real time has become important in various applications  (display tech, biomed sensors, imaging devices, diagnostic tools) >>

AA << use phononic crystals to tune sound fields in a microfluidic channel for controllable manipulation of microparticles and cells. An arbitrary stop-and-go motion of particles and cells along a predefined path in the channel is experimentally demonstrated. >>

Fei Li, Feiyan Cai, et al.  Phononic-Crystal-Enabled Dynamic Manipulation of Microparticles and Cells in an Acoustofluidic Channel.  Phys. Rev. Applied 13, 044077. Apr 30, 2020.

https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.13.044077

Controlling Particle Movements with Sound Waves. Physics 13, s58. Apr 30, 2020.

https://physics.aps.org/articles/v13/s58

# 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

# evol: echolocation, a prime example of convergent evolution

<< Echolocation is a prime example of convergent evolution, the independent gain of similar features in species of different lineages. >>

<< Distantly related species entering similar biological niches often adapt by evolving similar morphological and physiological characters. How much genomic molecular convergence (particularly of highly constrained coding sequence) contributes to convergent phenotypic evolution, such as echolocation in bats and whales, is a long-standing fundamental question.  >>

AA << find that the gene set most overrepresented (q-value = 2.2e-3) with convergent substitutions in echolocators, affecting 18 genes, regulates development of the cochlear ganglion, a structure with empirically supported relevance to echolocation. >>

Amir Marcovitz, Yatish Turakhia, et al. A functional enrichment test for molecular convergent evolution finds a clear protein-coding signal in echolocating bats and whales.
PNAS doi: 10.1073/pnas.1818532116   Sep 30, 2019    https://www.pnas.org/content/early/2019/09/27/1818532116 

Krista Conger. Scientists uncover genetic similarities among species that use sound to navigate. Stanford University Medical Center. Oct 4, 2019.   https://m.phys.org/news/2019-10-scientists-uncover-genetic-similarities-species.html

# sec: adversarial audio attacks; small sound perturbations to hack a Machine Learning model and remedies

<< Adversarial audio attacks can be considered as a small perturbation unperceptive to human ears that is intentionally added to the audio signal and causes a machine learning model to make mistakes. >>

Mohammad Esmaeilpour, Patrick Cardinal, Alessandro Lameiras Koerich. A Robust Approach for Securing Audio Classification Against Adversarial Attacks. arXiv:1904.10990 [cs.LG] Apr 24, 2019.

https://arxiv.org/abs/1904.10990

Ingrid Fadelli. An approach for securing audio classification against adversarial attacks. May 7, 2019.

https://m.techxplore.com/news/2019-05-approach-audio-classification-adversarial.html

# gst: (you must) read the noise as a message

<< Noise is often thought to be a nuisance with negative consequences, (..)  But through this study we show that noise can actually be used as a salient informational cue. It can provide individuals with important information about their environment and when it's safe to hunt. >> Inga Geipel

When does noise become a message?  Smithsonian Tropical Research Institute. Feb 6, 2019.

https://m.phys.org/news/2019-02-noise-message.html

<< Background noise can have strong negative consequences for animals, reducing individual fitness by masking communication signals, impeding prey detection and increasing predation risk. While the negative impacts of noise across taxa have been well documented, the use of noise as an informational cue, providing animals with reliable information on environmental conditions, has been less well studied. >>

Inga Geipel, Marcus J. Smeekes, et al. Noise as an informational cue for decision-making: the sound of rain delays bat emergence. Journal of Experimental Biology 2019 222: jeb192005 doi: 10.1242/jeb.192005 Feb 1, 2019.

http://jeb.biologists.org/content/222/3/jeb192005

Also

"noise" | "rumore"

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

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

# gst: even repulsive interactions generate solitons

<< Solitons are nonspreading wave packets that exist in a wide range of real-world systems, including water waves, sound, DNA, optics, and so on. >>

<< Two or more solitons can bind together to form a soliton molecule with dynamics similar to matter molecules, such as vibration, synthesis, and dissociation. >>

<< Formation processes for three types of soliton molecules were studied: ground-, excited-state, and a new one termed an intermittent-vibration soliton molecule. While it is generally believed that attractive interactions of solitons are responsible for the formation of soliton molecules, the authors found that soliton interactions are not limited to attractive interactions. Counterintuitively, even repulsive interactions can lead to the formation of soliton molecules, >>

John Wallace. Investigation with a femtosecond fiber laser finds new type of soliton ‘molecule’. Aug 01, 2018.

https://www.laserfocusworld.com/articles/print/volume-54/issue-08/newsbreaks/investigation-with-a-femtosecond-fiber-laser-finds-new-type-of-soliton-molecule.html

<< For closely‐separated bound solitons, soliton interactions display wide diversities in repeated measurements, including soliton attraction, repelling, collision, vibration, and annihilation. For well‐separated bound solitons, repulsive interactions dominate the soliton interactions. >>

Junsong Peng, Heping Zeng. Build‐Up of Dissipative Optical Soliton Molecules via Diverse Soliton Interactions. Laser & Photonics Reviews 2018, 12, 1800009.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/lpor.201800009 

Also "soliton" in:

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

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

# phys: where a drum can vibrate and stand still at the same time ...

<< Mechanical vibrations, such as those that create the sound from a drum, are an important part of our everyday experience. Hitting a drum with a drumstick causes it to rapidly move up and down, producing the sound we hear. In the quantum world, a drum can vibrate and stand still at the same time >>

Hayley Dunning. Can a quantum drum vibrate and stand still at the same time? Imperial College London. May 18, 2018.

https://m.phys.org/news/2018-05-quantum-vibrate.html

<< to control  the motion of  macroscopic mechanical resonators (..) to explore and exploit quantum phenomena at a macroscopic scale >>

Ringbauer M, Weinhold TJ, et al. Generation of mechanical interference fringes by multi-photon counting. New Journal of Physics. 2018; 20. May 18, 2018.

http://iopscience.iop.org/article/10.1088/1367-2630/aabb8d/meta

FonT

ecco una sfida per un percussionista  indiano ...(Dha, Dhin, Ta, Tin, Ti, ...)

# ecol: a live streaming audio from the depths (of the sea)

<< Starting this week, anyone can eavesdrop on sounds in the deep sea via a continuous streaming YouTube video that carries live sound from 900 meters (3,000 feet) below the surface of Monterey Bay >>

Kim Fulton-Bennett. Eavesdropping on the deep-New live streaming audio from a deep-sea hydrophone. Monterey Bay Aquarium Research Institute. Apr 24, 2018.

https://www.mbari.org/hydrophone-stream-release/

https://m.phys.org/news/2018-04-eavesdropping-deepnew-streaming-audio-deep-sea.html

Live stream from a deep-ocean soundscape.

https://www.mbari.org/deep-sea-sound-recordings-live-stream/