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sabato 25 gennaio 2025

# life: the Age of hallucinatory artificial intelligence (AI); the beginning.

<< It’s well known that all kinds of generative AI, including the large language models (LLMs) behind AI chatbots, make things up. This is both a strength and a weakness. It’s the reason for their celebrated inventive capacity, but it also means they sometimes blur truth and fiction, inserting incorrect details into apparently factual sentences. >>

<< They sound like politicians, they tend to make up stuff and be totally confident no matter what. >> Santosh Vempala. ️

<< Chatbots err for many reasons, but computer scientists tend to refer to all such blips as hallucinations. It’s a term not universally accepted, with some suggesting ‘confabulations’ or, more simply, ‘bullshit’. The phenomenon has captured so much attention that the website Dictionary.com picked ‘hallucinate’ as its word of the year for 2023. >>️

<< Because AI hallucinations are fundamental to how LLMs work, researchers say that eliminating them completely is impossible. >>️

Nicola Jones. AI hallucinations can’t be stopped — but these techniques can limit their damage. Nature. 637, 778-780. Jan 21,  2025. 

Also: ai (artificial intell) (bot), nfulaw, in https://www.inkgmr.net/kwrds.html 

Keywords: life, ai, artificial intell, LLMs, bot, nfulaw


venerdì 24 gennaio 2025

# gst: scattered waves fuel emergent activity.


<< Active matter taps into external energy sources to power its own processes. Systems of passive particles ordinarily lack this capacity, but can become active if the constituent particles interact with each other nonreciprocally. By reformulating the theory of classical wave-matter interactions, (AA) demonstrate that interactions mediated by scattered waves generally are not constrained by Newton's third law. The resulting center-of-mass forces propel clusters of scatterers, enabling them to extract energy from the wave and rendering them active. This form of activity is an emergent property of the scatterers' state of organization and can arise in any system where mobile objects scatter waves. Emergent activity flips the script on conventional active matter whose nonreciprocity emerges from its activity, and not the other way around. >>

AA << combine theory, experiment, and simulation to illustrate how emergent activity arises in wave-matter composite systems and to explore the phenomenology of emergent activity in experimentally accessible models. These preliminary studies suggest that heterogeneity is a singular perturbation to the dynamics of wave-matter composite systems, and induces emergent activity under all but the most limited circumstances. >>️

Ella M. King, Mia C. Morrell, et al. Scattered waves fuel emergent activity. Phys. Rev. Research 7, 013055. Jan 15, 2025

Also: waves, particle, self-assembly, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, waves, particle, self-assembly


giovedì 23 gennaio 2025

# gst: apropos of viscoelastic flow instabilities, uncertainty in elastic turbulence.

<< Elastic turbulence can lead to increased flow resistance, mixing and heat transfer. Its control - either suppression or promotion - has significant potential, and there is a concerted ongoing effort by the community to improve our understanding. >>

AA << identify four regimes of uncertainty evolution, characterised by I) rapid transfer to large scales, with large scale growth rates of τ6 (where τ represents time), II) a dissipative reduction of uncertainty, III) exponential growth at all scales, and IV) saturation. These regimes are governed by the interplay between advective and polymeric contributions (which tend to amplify uncertainty), viscous, relaxation and dissipation effects (which reduce uncertainty), and inertial contributions. >>

<< In elastic turbulence, reducing Reynolds number increases uncertainty at short times, but does not significantly influence the growth of uncertainty at later times. At late times, the growth of uncertainty increases with Weissenberg number, with decreasing polymeric diffusivity, and with the logarithm of the maximum length scale, as large flow features adjust the balance of advective and relaxation effects. >>

Jack R. C. King, Robert J. Poole, et al. Uncertainty in Elastic Turbulence. arXiv: 2501.09421v1 [physics.flu-dyn]. Jan 16, 2025. 

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

Keywords: gst, uncertainty, elastic, elasticity, turbulence 



martedì 21 gennaio 2025

# life: dear Mr. Donald, fuzzy evidence should be sharper, sooner or later, by Nature

       Nature | 637 | 16 Jan 2025 | 517

<< Mr President-elect, science is a self-correcting process in which bad actors and wrong ideas sooner or later get rooted out and fuzzy evidence becomes sharper. That is the joy and the beauty of the method that has made the modern world what it is. >>️

Editorial. Dear Donald Trump: A letter from Nature on how to make science thrive. Nature 637, 517. Jan 15, 2025.

Also: Mr. Donald, forms of power, virus, sars* covid* (aka 1or2achoos), dance, are you ready for all this, in https://www.inkgmr.net/kwrds.html 

Also: A new exception within the FDA Cures Act Informed Consent, the intriguing concept of 'Minimal Risk Clinical Investigations'. FonT. Feb 1, 2024. 

Also: 'acad' in FonT https://flashontrack.blogspot.com/search?q=acad    in Notes (quasi-stochastic poetry) https://inkpi.blogspot.com/search?q=acad 

Keywords: life, Mr. Donald, forms of power, virus, sars, covid, 1or2achoos, acad, dance, are you ready


sabato 18 gennaio 2025

# gst: traveling strings of active dipolar colloids.

AA << study an intriguing new type of self-assembled active colloidal polymer system in 3D. It is obtained from a suspension of Janus particles in an electric field that induces parallel dipoles in the particles as well as self-propulsion in the plane perpendicular to the field. >>

<< At low volume fractions, in experiment, the particles self-assemble into 3D columns that are self-propelled in 2D. Explicit numerical simulations combining dipolar interactions and active self-propulsion find an activity dependent transition to a string phase by increasing dipole strength. >>

AA << classify the collective dynamics of strings as a function of rotational and translational diffusion. (..) (They) also discover long range correlations of the fluctuations along the string contour that grow with the active persistence time, a purely active effect that disappears in the thermal limit. >>

Xichen Chao, Katherine Skipper, et al. Traveling Strings of Active Dipolar Colloids. Phys. Rev. Lett. 134, 018302. Jan 6, 2025. 

Also: particle, colloids, self-assembly, transition, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, particle, colloids, self-assembly, Janus, polymers, strings, transition


venerdì 17 gennaio 2025

# gst: diffusion of active particles driven by odd interactions.

<< Odd systems do not conserve energy, violate time-reversal symmetry, and remain far from equilibrium. How odd interactions between particles affect their diffusion remains unknown. >>

<< To investigate this issue, (AA) studied the diffusion and glass transition of a two-dimensional Kob-Andersen mixture, where Brownian particles interact via the Lennard-Jones potential and nonconservative odd forces. (Their) findings indicate a significant influence of odd interactions on the system's diffusion dynamics. Odd interactions always promote diffusion. These interactions lead to a nonmonotonic relationship between the effective diffusion coefficient and particle number density. >>

<< Specifically, in systems with low oddness, the diffusion coefficient decreases steadily with increasing particle number density. Conversely, in systems with moderate oddness, an optimal particle number density exists that maximizes the diffusion coefficient. For systems with high oddness, (AA) observe two distinct peaks in the diffusion coefficient-particle number density relationship. >>

<< Furthermore, (AA) investigation into the glass transition under dense conditions reveals that adjusting the oddness at low temperatures can induce a transition from a glassy state to a liquid state. >>

Rui-xue Guo, Jia-jian Li, Bao-quan Ai.
Diffusion of active particles driven by odd interactions. Phys. Rev. E 111, 014105. Jan 3, 2025.


Keywords: gst, particles, diffusion, 
active brownian particles, oddness, odd interactions


giovedì 16 gennaio 2025

# gst: chaotic dynamics creates and destroys branched flow.

<< The phenomenon of branched flow, visualized as a chaotic arborescent pattern of propagating particles, waves, or rays, has been identified in disparate physical systems ranging from electrons to tsunamis, with periodic systems only recently being added to this list. >>

Here, AA << explore the laws governing the evolution of the branches in periodic potentials. On one hand, (They) observe that branch formation follows a similar pattern in all nonintegrable potentials, no matter whether the potentials are periodic or completely irregular. Chaotic dynamics ultimately drives the birth of the branches. >>

<< On the other hand, (AA) results reveal that for periodic potentials the decay of the branches exhibits new characteristics due to the presence of infinitely stable branches known as superwires. Again, the interplay between branched flow and superwires is deeply connected to Hamiltonian chaos. >>

Alexandre Wagemakers, Aleksi Hartikainen, et al. Chaotic dynamics creates and destroys branched flow. Phys. Rev. E 111, 014214. Jan 7, 2025.
arXiv: 2406.12922v2 [nlin.PS]. 

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

Keywords: gst, chaos, waves, branched flows, superwires, transitions