Power emergentism and the collapse problem

Strong emergentism is the position that certain higher-level properties display a kind of metaphysical autonomy from the lower-level properties in which they are grounded. The prospect of collapse is a problem for strong emergentism. According to those who press the collapse problem any purportedly strongly emergent feature inheres in the emergence base, and so is not genuinely autonomous from that base. Recently, Umut Baysan and Jessica Wilson have argued that power emergentism avoids the collapse problem. In this paper, I challenge the claim that power emergentism avoids the collapse problem, and argue for explanatory emergentism in its place.

Closed microbial communities self-organize to persistently cycle carbon

Cycles of nutrients (N, P, etc.) and resources (C) are a defining emergent feature of ecosystems. Cycling plays a critical role in determining ecosystem structure at all scales, from microbial communities to the entire biosphere. Stable cycles are essential for ecosystem persistence because they allow resources and nutrients to be regenerated. Therefore, a central problem in ecology is understanding how ecosystems are organized to sustain robust cycles. Addressing this problem quantitatively has proved challenging because of the difficulties associated with manipulating ecosystem structure while measuring cycling. We address this problem using closed microbial ecosystems (CES), hermetically sealed microbial consortia provided with only light. We develop a technique for quantifying carbon cycling in hermetically sealed microbial communities and show that CES composed of an alga and diverse bacterial consortia self-organize to robustly cycle carbon for months. Comparing replicates of diverse CES, we find that carbon cycling does not depend strongly on the taxonomy of the bacteria present. Moreover, despite strong taxonomic differences, self-organized CES exhibit a conserved set of metabolic capabilities. Therefore, an emergent carbon cycle enforces metabolic but not taxonomic constraints on ecosystem organization. Our study helps establish closed microbial communities as model ecosystems to study emergent function and persistence in replicate systems while controlling community composition and the environment.

A Traditional Scientific Perspective on the Integrated Information Theory of Consciousness

This paper assesses two different theories for explaining consciousness, a phenomenon that is widely considered amenable to scientific investigation despite its puzzling subjective aspects. I focus on Integrated Information Theory (IIT), which says that consciousness is integrated information (as ϕMax) and says even simple systems with interacting parts possess some consciousness. First, I evaluate IIT on its own merits. Second, I compare it to a more traditionally derived theory called Neurobiological Naturalism (NN), which says consciousness is an evolved, emergent feature of complex brains. Comparing these theories is informative because it reveals strengths and weaknesses of each, thereby suggesting better ways to study consciousness in the future. IIT’s strengths are the reasonable axioms at its core; its strong logic and mathematical formalism; its creative “experience-first” approach to studying consciousness; the way it avoids the mind-body (“hard”) problem; its consistency with evolutionary theory; and its many scientifically testable predictions. The potential weakness of IIT is that it contains stretches of logic-based reasoning that were not checked against hard evidence when the theory was being constructed, whereas scientific arguments require such supporting evidence to keep the reasoning on course. This is less of a concern for the other theory, NN, because it incorporated evidence much earlier in its construction process. NN is a less mature theory than IIT, less formalized and quantitative, and less well tested. However, it has identified its own neural correlates of consciousness (NCC) and offers a roadmap through which these NNCs may answer the questions of consciousness using the hypothesize-test-hypothesize-test steps of the scientific method.

System Approach in Road Safety Studies

The road safety management methodology should be based on a system approach. This means that the road transport must be formalized as a complex system (CS), and then safety can be interpreted as an emergent feature of such a system. Road accidents should be interpreted as "organizational accidents". They should be studied using concepts such as "normal accident theory" (NAT) and "highly reliable organization" (HRO). The main purpose of the article is to show the usefulness of these concepts for the road safety and risk management, especially in Polish conditions. The system approach to road safety research (and transport safety) will allow for the better safety results.

The Western Tibetan Vortex as an emergent feature of near-surface temperature variation?

<p>The Western Tibetan Vortex (WTV) was identified through research efforts to understand the causal mechanisms responsible for the ‘Karakoram Anomaly’. The WTV has been shown to be an important anomalous circulation system influencing near surface climate over the Tibetan Plateau (TP). Existing researches have characterised the dynamical characteristics and thermodynamic behaviours of the WTV in detail. Scientific consensus has not yet been established. However, regarding the physical mechanisms which produce the WTV itself, a recent argument has asserted that the WTV is the set of wind field anomalies resulting from changes in 2m near-surface air temperatures (T<sub>2m</sub>) over the western TP. This argument can spur constructive discussion for improving our understanding on the WTV. This paper examines whether a putative thermal-generating machanism for the WTV can explain the established defining features of the WTV. In particular we evaluate if warmer (colder) T<sub>2m</sub> over the western TP is sufficient to drive downward (upward) wind anomaly in the overlying air column. Detailed consideration is given to whether the supposedly thermally induced vortex does indeed have the expected baroclinic structure – i.e. cyclonic (anti-cyclonic) wind anomaly at the mid-lower (mid-higher) troposphere – rather than a quasi-barotropic structure – i.e. cyclonic or anti-cyclonic wind anomaly at both the mid-lower and mid-higher troposphere –  as the research first identifying the WTV reported. This work thus seeks to determine the ‘direction of causality’ of whether  the WTV drives T<sub>2m</sub> over the western TP or the thermal forcing of the western TP’s T<sub>2m</sub> is the mechanism generating the WTV. This work utilises ERA5 meteorological reanalysis data to assess how the WTV may impact the western TP’s T<sub>2m</sub> through modulating the cloud cover and hence net surface radiation. These analyses complement previously published evaluation of the prosoposed adiabatic heating mechimism through which the WTV impacts the mid-lower tropospheric and near surface air temperarure. It is important to note that further evaluations of the skill of the newly released ERA5 dataset in representing the atmospheric conditions accurately over the western TP are still needed.</p>

Topological properties of aftershock clusters in a viscoelastic model of quasi-brittle failure

<p>Material failure at different scales and processes can be modeled as an emergent feature in terms of avalanche dynamics in micromechanical systems. <br>Event-event triggering -or aftershocks- is common in seismological catalogs and acoustic emission experiments <sup>[1]</sup> among other phenomena.<br>Stochastic branching and linear Hawkes processes are used to model the statistical properties of catalogs.  In the micromechanical approach, viscoelastic stress transfer and after-slip are among the proposed mechanism of aftershocks. Here we ask this simple question: '<em>Do aftershock sequences in micromechanical models agree with such epidemic branching paradigm?</em>'</p><p><br>We introduce two fibrous models as prototypes of viscoelastic fracture <sup>[2]</sup> which <em>(i)</em> provides an analytical explanation to the acceleration of activity in absence of critical failure observed in acoustic emission experiments <sup>[3]</sup>; <em>(ii)</em> reproduce the typical spatio-temporal properties of triggering found in field catalogs, acoustic emission experiments; but <em>(iii)</em> display discrepancies with the branching topological properties predicted by stochastic models <sup>[4]</sup>, probably due to physical constrains. <br><br>[1] J. Baró et al.,<em> Phys. Rev. Lett.</em> <strong>110</strong> (8), 088702 (2013).<br>[2] J. Baró, J. Davidsen, <em>Phys. Rev. E</em>  <strong>97</strong> (3), 033002 (2018).<br>[3] J. Baró, et al., <em>Phys. Rev. Lett.</em> <strong>120</strong> (24), 245501 (2018).<br>[4] S. Saichev, et al., <em>Pure and App. Geoph.</em> <strong>162</strong> (6), 1113-1134 (2005).</p>

The Western Tibetan Vortex as an emergent feature of near-surface temperature variations

<p>Glaciers are growing in a part of High Mountain Asia (HMA), contrary to the demise of glaciers worldwide. A proposed explanation for this behaviour is the decreasing strength of the "Western Tibetan Vortex" (WTV), a circular motion of air in the troposphere around northwestern High Mountain Asia, which is proposed to drive near-surface temperatures. Here, we show that the WTV is the change of wind field resulting from changes in near-surface temperature, and that it is not unique to northwestern HMA, but is generally applicable to large parts of the globe. Instead, we argue that net radiation is likely the main driver of near-surface temperatures in Western HMA in summer and autumn, and that the WTV is the response of the atmosphere to changes in temperature. The decreasing strength of the WTV, as seen during summer in the 20th century, is thus likely the result of changing net radiation, and not the main driver of cooling itself. We do argue that the WTV is a useful concept to understand large scale climate variability in the region, and that such an approach could yield important insights in other mid-latitude regions as well.</p>

Epistasis between cultural traits causes paradigm shifts in cultural evolution

Every now and then the cultural paradigm of a society changes. While current models of cultural shifts usually require a major exogenous or endogenous change, we propose that the mechanism underlying many paradigm shifts may just be an emergent feature of the inherent congruence among different cultural traits. We implement this idea through a population dynamics model in which individuals are defined by a vector of cultural traits that changes mainly through cultural contagion, biased by a ‘cultural fitness’ landscape, between contemporary individuals. Cultural traits reinforce or hinder each other (through a form of cultural epistasis) to prevent cognitive dissonance. Our main result is that abrupt paradigm shifts occur, in response to weak changes in the landscape, only in the presence of epistasis between cultural traits, and regardless of whether horizontal transmission is biased by homophily. A relevant consequence of this dynamics is the irreversible nature of paradigm shifts: the old paradigm cannot be restored even if the external changes are undone. Our model puts the phenomenon of paradigm shifts in cultural evolution in the same category as catastrophic shifts in ecology or phase transitions in physics, where minute causes lead to major collective changes.

The clockwork is moving on – a combined analysis of TESS and Kepler measurements of Kepler-13Ab

ABSTRACT Kepler-13Ab (KOI-13) is an exoplanet orbiting a rapidly rotating A-type star. The system shows a significant spin–orbit misalignment and a changing transit duration most probably caused by the precession of the orbit. Here, we present a self-consistent analysis of the system combining Kepler and Transiting Exoplanet Survey Satellite (TESS) observations. We model the light curves assuming a planet transits a rotating oblate star that has a strong surface temperature gradient due to rotation-induced gravity darkening. The transit chord moves slowly as an emergent feature of orbital precession excited by the oblate star with a decline rate in the impact parameter of db/dt = −0.011 yr−1, and with an actual value of b = 0.19 for the latest TESS measurements. The changing transit duration that was measured from Kepler Q2 and Q17 quarters and the TESS measurements indicates a linear drift of the impact parameter. The solutions for the stellar spin axis suggest a nearly orthogonal aspect, with inclination around 100°.