III. Ecosmos: A Revolutionary Fertile, Habitable, Solar-Bioplanet, Incubator Lifescape

2. Computational Systems Physics: Self-Organization, Active Matter

Drossel, Barbara. Strong Emergence in Condensed Matter Physics. arXiv:1909.01134. In a contribution to appear in a Synthese issue on Top-Down Causation, the Technical University Darmstadt theoretical physicist (search) contends that from a 2019 vista this basic field, aka many-body physics, by virtue of integrative summations of myriad particles (entities), does inherently give rise to macroscopic formations. See also How Downwards Causation Occurs in Digital Computers by George Ellis and the author at 1908.10186 and Emergent Quasiparticles by Alexandre Guay and Olivier Sartenaer in Individuation, Process, and Scientific Practices by Otavio Bueno, et al, eds. (Oxford UP, 2018).

This paper argues that the physics of condensed matter cannot be reduced to the supposedly fundamental quantum mechanical theory for all the atoms of which the system consists. In fact, there are many reasons to reject the idea that the world of physics is causally closed with everything being determined by bottom-up by microscopic laws. In actual practice condensed-matter theory does not start with atomic interactions. Instead, plausible assumptions, intuitive models, and phenomena are used to mathematically describe the properties of systems that consist of a macroscopic number of particles. The paper thus includes a list of arguments in favor of strong emergence and top-down causation within the realm of physics. (Abstract excerpt)

Elaiw, Ahmed, et al. On Entropy Dynamics for Active “Living” Particles. Entropy. Online October, 2017. King Abdulaziz University, Saudi Arabia system physicists including Nicola Bellomo (search) consider this newly perceived feature of physical materiality to inherently self-organize into animate assemblies. If to consider this work, and e.g., a cosmology paper by the Iranian physicists Khanpour and Yusofi (search), might a palliative 21st century renaissance of Islamic science be actually be underway? See also these concurrent books by the authors: A Quest Towards a Mathematical Theory of Living Systems and Active Particles: Advances in theory, Models, and Applications, see second quote, both from Springer/Birkhauser.

This paper presents a modeling approach, followed by entropy calculations of the dynamics of large systems of interacting active particles viewed as living—hence, complex—systems. Active particles are partitioned into functional subsystems, while their state is modeled by a discrete scalar variable, while the state of the overall system is defined by a probability distribution function over the state of the particles. The aim of this paper consists of contributing to a further development of the mathematical kinetic theory of active particles. (Abstract)

This volume collects ten surveys on the modeling, simulation, and applications of active particles using methods ranging from mathematical kinetic theory to nonequilibrium statistical mechanics. The contributing authors are leading experts working in this challenging field, and each of their chapters provides a review of the most recent results in their areas and looks ahead to future research directions. The approaches to studying active matter are presented here from many different perspectives, such as individual-based models, evolutionary games, Brownian motion, and continuum theories, as well as various combinations of these. Applications covered include biological network formation and network theory; opinion formation and social systems; control theory of sparse systems; theory and applications of mean field games; population learning; dynamics of flocking systems; vehicular traffic flow; and stochastic particles and mean field approximation. (AP summary)

Ellis, George F. R. Physics and the Real World. Foundations of Physics. 36/2, 2006. A brief version appeared in Physics Today, July 2005. An exercise to better relate and square physical reality with the presence of risen life. But what kind of universe is Ellis trying to describe. Not the moribund megaverse of string theory whereof human beings are the most fleeting, insignificant anomaly. By such inherent animate properties cosmic matter is seen to develop into emergent modular hierarchies of sentient and creative entities, in so many words a natural genesis.

The challenge to physics is to develop a realistic description of causality in truly complex hierarchical structures, with top-down causation and memory effects allowing autonomous higher levels of order to emerge with genuine causal powers. (227)

Eom, Young-Ho, et al. Network-Based Model of the Growth of Termite Nests. Physical Review E. 92/6, 2015. Systems scientists across Europe including Santo Fortunato and Guy Theraulaz analyze social insect structures in terms of local node and interactive link complexity, which is then seen as a generic instance of a universal self-organization phenomena. We cite as another example of mid 2010s abilities to study and perceive both these specific instantiations and their common, independent mathematics.

We present a model for the growth of the transportation network inside nests of the social insect subfamily Termitinae (Isoptera, termitidae). These nests consist of large chambers (nodes) connected by tunnels (edges). The model based on the empirical analysis of the real nest networks combined with pruning (edge removal, either random or weighted by betweenness centrality) and a memory effect (preferential growth from the latest added chambers) successfully predicts emergent nest properties (degree distribution, size of the largest connected component, average path lengths, backbone link ratios, and local graph redundancy). Our results provide an example of how complex network organization and efficient network properties can be generated from simple building rules based on local interactions and contribute to our understanding of the mechanisms that come into play for the formation of termite networks and of biological transportation networks in general. (Abstract)

Fontaine, Quentin, et al.. Kardar-Parisi-Zhang Universality in a One-Dimensional Polariton Condensate. Nature. August 24, 2022. Sixteen physicists in France, Belgium and Italy mainly at the University of Paris-Saclay cite experimental instances of consistent, reliable formations that occur across many “physical” occasions. (a reason why we added Statistical Organics to the section title). See a review A New Phase for the Universal Growth of Interfaces by Sebastian Diehl in the same issue which lauds the quality and wider significance of these findings.

Revealing universal behaviours is a hallmark of statistical physics. Phenomena such as the stochastic growth of crystalline surfaces and of interfaces in bacterial colonies, and spin transport in quantum magnets all belong to the same universality class, despite wide microscopic differences. In each systems, space–time correlations show power-law scalings with similar critical exponents, a dynamic commonality governed by the nonlinear stochastic Kardar–Parisi–Zhang (KPZ) equation (see Wikipedia, G. Parisi is a 2021 Nobel winner). Our empirical studies show that phase evolutions in a driven-dissipative one-dimensional polariton condensate indeed holds to the KPZ universality class. (Abstract excerpt)

Freivogel, Ben. A Multiverse of Probabilities. Physics World. March, 2010. I put this paper here to emphasize the present absence of systems thinking in physical cosmology. For the situation is dire. Physicists seem to be spinning their 11 dimension, string, brane, tangled theories to incoherent extremes, quite unawares, with no faculty, quality control, or philosophical oversight as a reality check. The postmodern humanities cheer because don’t you know there is no reality to check, only bubble cosmoses, each with vicarious laws and constants. And this article is not isolated, in the April 2010 issue of Discover magazine three “Beyond Einstein” articles traipse hypotheses all over matter, space and time. While the March 30 news, as I write, proclaims the LHC is finally smashing atoms, in this same PW issue it is lamented that the supposed keystone Higgs boson may be more elusive than thought. Just how Ptolemaic will physics become, spinning epicycles from particles to parsecs, sans any admissible sense, the very idea, of a greater knowable genesis creation.

Frey, Erwin. Evolutionary Game Theory: Theoretical Concepts and Applications to Microbial Communities. Physica A.. 389/4265, 2010. A Ludwig-Maximilians-Universität München biophysicist provides a 33 page tutorial on the merger of stochastic physics with nonlinear complex network science. The material was presented at 2009 summer schools such as “Condensed Matter and Materials Physics” in Boulder, Colorado, and “Steps in Evolution: Perspectives from Physics, Biochemistry and Cell Biology 150 Years after Darwin” at Jacobs University, Bremen. By what worldwide natural philosophy might we begin to realize the actual discovery of a genesis cosmos with such vital propensities from universe to human?

Ecological systems are complex assemblies of large numbers of individuals, interacting competitively under multifaceted environmental conditions. Recent studies using microbial laboratory communities have revealed some of the self-organization principles underneath the complexity of these systems. A major role of the inherent stochasticity of its dynamics and the spatial segregation of different interacting species into distinct patterns has thereby been established. It ensures the viability of microbial colonies by allowing for species diversity, cooperative behavior and other kinds of “social” behavior. A synthesis of evolutionary game theory, nonlinear dynamics, and the theory of stochastic processes provides the mathematical tools and a conceptual framework for a deeper understanding of these ecological systems. We conclude with a perspective on the current challenges in quantifying bacterial pattern formation, and how this might have an impact on fundamental research in non-equilibrium physics. (Abstract excerpts)

Furusawa, Chikara and Kunihiko Kaneko. Evolutionary Origin of Power-Laws in a Biochemical Reaction Network. Physical Review E. 73/011912, 2006. An example of how constant, “inevitable” properties and propensities can be extracted from all kinds of naturally occurring organic metabolic dynamics.

Therefore, one possible strategy for extracting the nature of intracellular dynamics is to search for universal laws with regard to the networks of intracellular reactions common to a class of cell models – albeit simple – and then to unravel the dynamics of evolution leading to such features. (011912-1)

Ghosh, Subhadip, et al. Enzymes as Active Matter. Annual Review of Condensed Matter. Vol. 12, 2020. Enzyme: a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction. Penn State biochemists contribute a further notice of this natural spontaneity in effect for metabolic processes. Are we persons “condensed Matter” or is the physical ecosmos coming to life. See also Stem Cell Populations as Self-Renewing Many-Particle Systems by David Jorg, et al in this same volume for another instance.

Nature has designed multifaceted cellular structures to support life. Cells contain a vast array of enzymes that collectively perform tasks by harnessing energy from chemical reactions. In the past decade, detailed investigations on enzymes that are freely dispersed in solution have revealed a concentration-dependent enhanced diffusion and chemotactic behavior during catalysis. The purpose of this article is to review the different classes of enzyme motility and discuss the possible mechanisms as gleaned from experimental observations and theoretical modeling. (Ghosh Abstract excerpt)

This article reviews the physical principles of stem cell populations as active many-particle systems that are able to self-renew, control their density, and recover from depletion. We illustrate the statistical hallmarks of homeostatic mechanisms from stem cell transient large-scale oscillation dynamics during recovery to the scaling behavior of clonal dynamics and front-like boundary propagation during regeneration. (Jorg Abstract)

Giardina, Irene. Collective Behavior in Animal Groups: Theoretical Models and Empirical Studies. HFSP Journal. 2/4, 2008. Noted more in Organic Societies, a Centre for Statistical Mechanics and Complexity, University of Rome, (Google for info) physicist achieves a novel advance for nonlinear science for not only is an exemplary complex, agent-based self-organization described for avian bird flocks, but this activity, widespread across animal communities from microbes and insects to primates and economies, is seen to imply and spring from a general, independent, informative source.

Goh, Segun, et al. Emergence of Criticality in the Transportation Passenger Flow: Scaling and Renormalization in the Seoul Bus System. PLoS One. 9/3, 2014. Seoul National University, Sungshin Women’s University, Seoul, and CNRS, Institut Jean Lamour, France physicists and geographers deftly discern in urban commuter traffic the presence of intrinsic self-organizing complex network phenomena. At the outset, the project is said to be a good example of statistical mechanics applied to social systems. We likewise cite this work as a microcosm of the worldwide discovery of a mathematical generative agency. Over the past two decades, intensely since 2010, an exemplary manifestation of these same nonlinear forms and dynamics has been found everywhere from cosmos to cities. A strong implication is then an independent, program-like source from which such a scale-invariant universality arises.

Social systems have recently attracted much attention, with attempts to understand social behavior with the aid of statistical mechanics applied to complex systems. Collective properties of such systems emerge from couplings between components, for example, individual persons, transportation nodes such as airports or subway stations, and administrative districts. Among various collective properties, criticality is known as a characteristic property of a complex system, which helps the systems to respond flexibly to external perturbations. This work considers the criticality of the urban transportation system entailed in the massive smart card data on the Seoul transportation network. Analyzing the passenger flow on the Seoul bus system during one week, we find explicit power-law correlations in the system, that is, power-law behavior of the strength correlation function of bus stops and verify scale invariance of the strength fluctuations.

Such criticality is probed by means of the scaling and renormalization analysis of the modified gravity model applied to the system. Here a group of nearby (bare) bus stops are transformed into a (renormalized) “block stop” and the scaling relations of the network density turn out to be closely related to the fractal dimensions of the system, revealing the underlying structure. Specifically, the resulting renormalized values of the gravity exponent and of the Hill coefficient give a good description of the Seoul bus system: The former measures the characteristic dimensionality of the network whereas the latter reflects the coupling between distinct transportation modes. It is thus demonstrated that such ideas of physics as scaling and renormalization can be applied successfully to social phenomena exemplified by the passenger flow. (Abstract)

Gompper, Gompper, Gerhard, et al. The 2019 Motile Active Matter Roadmap. Journal of Physics: Condensed Matter. 32/29, 2020. This is a broadly European state of the art collection for this fluid field, which is hardly a decade old. As the quotes note, some 40 researches post papers such as Active Brownian Particles: From Collective Phenomena to Fundamental Physics by Thomas Speck, Self-organized Collective Patterns by Fernando Peruani, and Patterns of Collective Motion in Huge Flocks of Starlings by Charlotte Hemelrijk. Its popularity and expansive subject increasingly attest to an animate, lively natural materiality.

Activity and autonomous motion are fundamental in living and engineering systems. The new field of active matter now focuses on the physical aspects of propulsion mechanisms, and on motility-induced collective behavior of a larger number of member agents. The scale ranges from microswimmers to cells, fish, birds, and people. A major challenge for understanding and designing active matter is their nonequilibrium nature due to persistent energy consumption. The vast complexity of phenomena and mechanisms involved in the self-organization and dynamics of motile active systems comprises a major challenge. Hence, going forward this important research area requires a concerted, synergetic, interdisciplinary approach. (Abstract excerpt)

Active matter is a novel class of nonequilibrium systems composed of a large number of autonomous agents. The scale of agents ranges from nanomotors, microswimmers, and cells, to crowds of fish, birds, and humans. Unraveling, predicting, and controlling the behavior of active matter is a truly interdisciplinary endeavor at the interface of biology, chemistry, ecology, engineering, mathematics, and physics. Recent progress in experimental and simulation methods, and theoretical advances, now allow for new insights into this behavior, which should ultimately lead to the design of novel synthetic active agents and materials. This Roadmap provides an overview of the state of the art, and discusses future research directions on natural and artificial active agents, and their collective behavior. (Gerhard Gompper, Roland Winkler, 3)

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