Physical Sciences

Abstract: Generative artificial intelligence is increasingly embedded in recursive informational ecosystems in which outputs are produced, published, retrieved, summarized, copied and pasted into new human or machine production. This paper proposes a preliminary predictive framework for Dissipative Semantic Homogenization (DSH), a possible re-gime in which recursive generative AI ecosystems dissipate physical energy while corpus-level semantic diversity contracts and saturates. The framework does not iden-tify thermodynamic entropy with semantic entropy. Instead, it treats them as opera-tionally coupled variables: semantic distributions are transformed by physically im-plemented computation, while energy dissipation provides a macroscopic cost proxy. We model semantic diversity as Shannon entropy over a corpus-level partition of se-mantic states and introduce modal amplification, independent novelty injection, and AI assimilation of nominally human production as control variables. The model yields empirically testable implications: semantic contraction should occur only when effec-tive independent novelty falls below a stability threshold; contraction should be scale-dependent; and cumulative semantic loss should saturate even while physical entropy production continues. The framework is not presented as an empirical law, but as a testable theoretical model for future longitudinal and controlled studies.

Abstract: It is shown that the Clausius entropy and the internal energy can be taken to be additive for systems existing next to each other, contemporaneously, and without relative speed. Also, it is shown that any thermodynamic state quantity is extensive if it is additive and if its volume density is finite. It is argued that for many state quantities the assumption of extensivity can be replaced by the assumption of finite density. The point of view is the macroscopic and non-statistical one of classical thermodynamics.

Abstract: This paper assumes that a thermodynamic system can be composed purely of coherence and information, and constructs a working model on that basis. We derive operational parameters for such systems using definitions of the Certainty Equation, semantic entropy, semantic temperature, and formulate five laws and three modes of coherence and information systems. This analysis is then compared to the features of black holes.

Abstract: The Gibbs Paradox (concerning the entropy of mixing and entropic extensivity) was explored in depth by Edwin Jaynes (1992). We take up Jaynes’ treatment, considering the special cases for which entropy is (approximately) extensive, and the general case in which it is not. We also explore the Holographic Principle which (strictly speaking) excludes the extensivity of entropy. The formalism of Quantitative Geometrical Thermodynamics shows that, being isomorphic to energy, it is entropy production (not entropy) that is extensive. As a corollary, Shannon information is also not extensive, although information production is extensive.

Abstract: Upper troposphere (UT) humidity records are crucial for climate studies. Pseudo-monthly averaging limited just to nighttime measurement is applied to maximize temporal representativeness and enhance the lidar signal, providing WVMR profiles up to 16 km. This study evaluates 11 years (2013–2023) of water vapor mixing ratio (WVMR) profiles from a UV Raman lidar (Lid1200) at Réunion Island against MLS-Aura satellite retrieval, ERA5 reanalysis, and GRUAN-processed M10 radiosondes. The results show a systematic dry shift in MLS of up to 30% above 12 km, particularly during the wet season. Lidar exhibits a slight downward shift in WVMR, around 5% lower than ERA5 throughout the UT, with the largest deviations present above 14 km and greater variability during the wet season, Lidar calibration-related challenges during the dry season result in drier-than-ERA5 WVMR profiles (up to 10%). Additionally, comparisons with GRUAN-processed radiosonde reveal a substantial dry shift relative to the lidar, exceeding 30% above 12 km. We investigate the GNSS-based lidar calibration effect by applying an alternative calibration method. This produces higher WVMR values, revealing an ERA5 dry shift relative to lidar, increasing with altitude at the UT up to 25%. These measurements complement the global effort in monitoring and validating the tropical and subtropical upper tropospheric humidity.

Abstract: A nano-porous tubular ceramic membrane(TCM) is developed to recover water vapor and its significant amount of latent heat from flue gas to save water and reduce the acid dew point. The experimental and numerical investigation on both normal condensation(NCD) and capillary condensation(CCD) by insetting a horizontal TCM into membrane module. By taking user defined function(UDF) of Fluent14.5, source terms of governing equations are conducted to illuminate the NCD, capillary condensation and effects of the inertia force(F_i) on heat and mass transfer. Several cases with feed gas inlet velocity(U_in), mass fraction of non-condensable gas (W_con), cooling water inlet temperature(T_cool) and time steps(t) are simulated, and the errors between experimental and numerical results are less than 1.14%. The results show that the thermal performance of TCM in the NCD is more significant than which in the CCD. The NCD proceeds significantly during flow in the TCM, while the CCD proceeds mainly in the backside of TCM(x-coordinate is larger than 500mm nearly). The U_in, W_con and T_cool have a remarkable effect on thermal and mass-transfer characteristics.

Abstract: The entropy of a Schwarzschild black hole is commonly derived using thermodynamic relations whose physical interpretation is not always transparent, in particular with re-spect to the localization of temperature and entropy. In this paper, we present a derivation of the Bekenstein–Hawking entropy based exclusively on the principles of phenome-nological thermodynamics, formulated entirely in regions where spacetime is effectively flat. The analysis considers a reversible evaporation process in which the black hole is sur-rounded by a tunable thermal radiation bath whose temperature is kept arbitrarily close to the Hawking temperature. In this limit, entropy production can be made negligible. By integrating the entropy flux through a distant reference surface over the evaporation process, the standard entropy formula is obtained without invoking assumptions about the localization of the black hole entropy or about microscopic degrees of freedom. The derivation is mathematically simple but conceptually instructive. The approach is intended to be accessible to readers familiar with classical thermodynamics and general relativity at an advanced undergraduate or graduate level.

Abstract: In the introduction, a brief history of the body selection that would define the inertial frame of reference in mechanics (and electrodynamics) is given. At the same time, attention has been drawn to Einstein's opinion about the (unrealized) causal relationship which should exist between the frame of reference and the law that is formulated from it. Therefore, parts 2 to 5 gradually present and elaborate the idea that, instead of directly choosing a body of reference, the criterion which will give legitimacy to the selection result should be defined first. And the criterion is such that the reference body is ensured by causality just mentioned by Einstein. Such a criterion for the fields of mechanics and thermodynamics is defined here and called the "criterion of observer's non-involvement in the observed” by a reference body. In the conclusion, as the main result, significant changes in the formulations of mechanics and thermodynamics, which the application of the criterion leads to, are stated. In those improved formulations the contents related to the observer are separated from the contents related to laws of nature.

Abstract: Metabolism in living things is the combination of enzyme-catalyzed biochemical reactions that drive biological work in the form of energy capture and release, molecule synthesis, cell replication and other functions. It is constrained by many factors, including resources, enzyme characteristics, and temperature under the requirement that organisms persist through time. Here, the biochemical foundation for metabolism is viewed from a thermodynamic perspective that explores three different metabolic currencies: (1) entropy production, which reflects the ability to persist at or near steady state through time by the rate at which entropy of surroundings is increased relative to that inside a system, (2) reaction rate or the rate of formation of products, and (3) power, the rate at which “free” (Gibbs) energy available for doing work is generated. Rate-temperature relationships for each objective are derived from a reaction-displacement model of a metabolic reaction for near-steady-state conditions, which are presumed to be required for organisms to persist over time. Reaction rate, entropy production and Gibbs energy production are maximized at different optimal temperatures, T_opt, all at barely distinguishable near-maximum reaction rates. These theoretical predictions nevertheless provide distinct, testable hypotheses for organism response to temperature under maximizing each of the three metabolic currencies. The framework also suggests that there exists a maximum temperature for life, T_max, at which entropy generated near reaction sites by reaction activation becomes greater than that generated away from reaction sites by the dissipation of heat and products. The framework predicts shifts in Topt and T_max that differ among types of reactions, enzyme concentrations, organism element concentration and varying body size. Overall, the framework provides a greatly expanded set of hypotheses and explanations for temperature performance relationships for life, including variation in both T_opt and T_max, for growth versus locomotion and respiration, “fast” versus “slow” life histories, resource-rich versus resource-poor environments, and intra- and interspecific variation in body size.

Abstract: This paper presents a practical implementation of relative primary radiation thermometry (RPRT) together with MultiFixRadSoft, an open-source software package developed in accordance with the Mise-en-Pratique for the kelvin (MeP-K) for realization of the thermodynamic temperature scale and uncertainty evaluation under the new definition of the kelvin. The software enables realization of temperature scales using ITS-90 metal fixed points as well as metal–carbon and metal–carbide–carbon eutectic high-temperature fixed points (HTFPs) for both radiation thermometers and radiometers. It incorporates automated routines for melting-plateau analysis, including determination of the point of inflection, liquidus point, and melting range, together with correction modules for size-of-source effect, detector nonlinearity, emissivity, and temperature-drop. Validation is demonstrated through experimental realization using six fixed points (Cu, Fe–C, Co–C, Pd–C, Ru–C, and WC–C) and a linear radiation thermometer. The software also supports ITS-90 extrapolation procedures and flexible calibration schemes (n = 1 to n ≥ 3), with automated Sakuma–Hattori fitting and full uncertainty propagation compliant with MeP-K requirements. Results show excellent agreement with manual analyses and published data, confirming the correctness of the implemented algorithms. By integrating data processing, scale realization, and uncertainty analysis within a unified and transparent framework, MultiFixRadSoft provides a robust and accessible tool for traceable radiometric thermometry, supporting emerging NMIs and industrial laboratories while promoting wider adoption of primary thermodynamic temperature realization methods.

Abstract: Redefining of the notions of econophysics based on the Landauer principle is suggested. Economic temperature is defined via the economic Landauer principle. The economic temperature is proportional to the minimal monetary cost associated with erasing or transmitting one bit of information in a given economic system. The introduced definition is useful for high-frequency trading. Clausius formulation of the Second Law of Thermodynamics for economic systems is formulated as follows: energy/money cannot spontaneously flow from a colder economic system to a hotter economic system. Carnot and Szilard’s economical engines are addressed. The Carathéodory formulation of the Second Law of Thermodynamics is re-shaped as follows: in every neighborhood of any equilibrium economic state, there exist states that cannot be reached by the process, which does not spend money or information. Optimal-power Curzon–Ahlborn economic engine is discussed.

Abstract: The burning candle discussed in Faraday's lectures is used as an example to discuss the relationships between physical theories at different levels of organization: continuum mechanics at the macro level and statistical and quantum mechanics at the micro level. The first part of the paper examines the connections between theoretical and experimental physics. Physics theory serves as the foundation of the research program, but experimental research is a measure of ongoing development. Reasonable extrapolationism denotes a situation where the ideas of physical theory contribute to the development of experimental research. On the other hand, radical extrapolationism is used for a situation where the ongoing discussion goes far beyond experimental physics. In the second part of the paper, the arrows of explanation between continuum mechanics and statistical mechanics are considered and classified within the framework of the proposed terminology. The estimation of the properties of a substance from molecular constants and the derivation of continuum mechanics equations from statistical mechanics are considered. Qualitative explanations and emergence are also discussed.

Abstract: We propose a thermodynamic variational framework in which quantum mechanics, classical dynamics, and gravitation emerge as equilibrium regimes of a single free-energy functional defined on probability distributions rather than on trajectories, wavefunctions, or spacetime metrics. The functional balances Fisher information, potential energy, and Shannon entropy, encoding an exploration–exploitation trade-off uniquely fixed by information-theoretic considerations. Matching the Fisher term to the quantum kinetic energy fixes its coefficient without free parameters. Extremization of the functional yields the continuity equation and the quantum Hamilton–Jacobi equation, and thus reproduces the Schrödinger equation as a thermodynamic equilibrium condition. At mesoscopic scales, competition between Fisher information and entropy introduces a characteristic quantum–classical crossover length that provides a thermodynamic perspective on decoherence. Measurement is interpreted as an irreversible thermodynamic transition, with energetic costs bounded by Landauer's principle. In the macroscopic regime, we show that requiring thermodynamic stability and local boundary response selects area-law entropy scaling as the leading contribution under stated assumptions. Given an area-law entropy, standard local arguments recover Einstein's field equations. The framework yields falsifiable predictions across quantum, mesoscopic, and gravitational regimes.

Abstract: Area-law entropy appears in quantum many-body systems and gravitational physics, whereas classical thermodynamics treats entropy as volume-extensive. Rather than reflecting competing fundamental principles, we show that these scalings correspond to distinct thermodynamic stability regimes. Using a minimal information-theoretic free-energy functional combining Fisher information and Shannon entropy, we analyze entropy scaling under three physically unavoidable requirements: locality of response, existence of thermodynamic equilibrium, and universality of gravitational coupling. Within this framework, we prove that volume-law entropy cannot define an intrinsically stable equilibrium for isolated macroscopic systems and is therefore viable only as an externally stabilized, mesoscopic approximation. We identify three regimes. At microscopic scales, Fisher dominance and locality of information propagation enforce area-law entropy. At intermediate scales, volume-law entropy emerges as a metastable regime sustained by non-gravitational confinement. At macroscopic scales dominated by self-gravity, we show that thermodynamic stability and composition-independent equilibrium uniquely require area-law entropy; any more extensive scaling leads either to instability or to violations of the equivalence principle. Volume-law entropy is thus identified as a mesoscopic anomaly rather than a fundamental property of matter. Area-law scaling emerges as the only entropy behavior consistent with a unified thermodynamic description spanning quantum coherence and gravitational universality.

Abstract: Statistical entropy introduced in Boltzmann's combinatorial argument played a crucial role in the development of modern physics, yet it is limited to ideal monatomic gases. Statistical mechanics developed by Gibbs is suitable for any system, and this approach yielded important practical results. Unfortunately, the Gibbs statistical entropy remains constant during an irreversible process in the isolated system. This led to the conclusion that entropy is subjective — that entropy of a system is related to ignorance or information gained by an external observer during measurement. At present, arguments for the objectivity of entropy are related to the microcanonical Boltzmann entropy in the system phase space. The advantages and disadvantages of the Boltzmann entropy are discussed. Carnap's principle of physical magnitudes is also considered.

Abstract: The persistent H0 and growth tensions in ΛCDM cosmology motivate a re-examination of the expansion paradigm’s foundational assumptions. The Dead Universe Theory (DUT) proposes an alternative in which observable galaxy separation is not due to metric expansion but results from irreversible, entropy-driven deformation of a viscoelastic spacetime continuum undergoing global gravitational retraction. This work formalizes DUT within a relativistic continuum-mechanics framework. We derive the entropic deformation tensor Ξ_μν from a variational principle and incorporate it into the Einstein field equations as G_μν + Ξ_μν = 8πG T_μν, replacing the cosmological constant with a dynamical, entropy-sourced curvature. A key prediction follows from the asymptotic stability analysis of the resulting system: a unique, non-adjustable growth index γ = (√5 − 1)/2 ≈ 0.6180339887…, the signature of the theory’s Unique Vacuum Attractor. Consequently, a high-precision measurement of the growth index consistent with γ ≈ 0.55 at the <0.01 level would strongly falsify DUT. This formulation provides a falsifiable, thermodynamically grounded geometric description of cosmic dynamics, directly linking late-time acceleration-like phenomena to residual entropy gradients of a “dead” gravitational substrate. Numerical validation of the attractor is available in the mission-grade inference pipeline (repository and preprint DOI provided in the Data/Code Availability statement).

Abstract: The thermodynamic behavior of many complex physical systems is strongly influenced by the structure of their underlying energy landscapes, particularly by the presence of exponentially many metastable states. While such landscape-level properties are central to the physics of glasses and disordered systems, they are not explicitly represented in standard thermodynamic state spaces. In this work, we develop a constrained equilibrium thermodynamic framework in which configurational complexity, defined as the logarithmic density of metastable states, is treated as an explicit macroscopic coordinate. Starting from the principle of maximum entropy, we construct equilibrium ensembles subject to simultaneous constraints on energy and configurational complexity, leading to a generalized Gibbs distribution characterized by a conjugate complexity control parameter. Within this framework, extended thermodynamic relations arise naturally as constrained equilibrium identities, without modification of the fundamental laws of thermodynamics. The formalism is illustrated through a worked example based on a mean-field glassy landscape, where configurational complexity can be computed explicitly. In this setting, complexity bias alters the saddle-point structure of the partition function, produces nontrivial response functions, and yields clear signatures of structural transitions. An extension to thermodynamic geometry further demonstrates how reorganizations of the energy landscape manifest as geometric features in an enlarged thermodynamic state space. The results presented here provide a systematic and physically grounded approach to incorporating landscape-level complexity into equilibrium thermodynamics. Rather than proposing universal energetic bounds, the framework offers a model-dependent tool for analyzing how configurational structure influences thermodynamic behavior in complex systems.

Abstract: Numerical studies on the dynamics of bubble clusters in a compressible fluid, including interfacial heat and mass transfer, were performed to investigate the behaviour of bubble clusters in cavita-tion devices. The influence of operational and system parameters on the intensity of cavitation processes was considered. Physicochemical transformations during the cavitation treatment of liquids are caused not only by the action of shock waves and emitted pressure pulses but also by extreme thermal effects. At the stage of ultimate bubble compression, the vapour inside the bubble and the liquid in its vicinity transition to a supercritical fluid state. The presented model analyses the nature of microflows in the inter-bubble space and performs a quantitative calculation of the local values of velocity and pressure field parameters.

Abstract: A mathematical Kelvin formulation of the second law of thermodynamics in the form of a limit is proposed: If the efficiency of a heat engine approaches unity, then the rejected work vanishes. This limit allows deriving the behavior of a Carnot cycle near absolute zero of temperature. Also, the unattainability of absolute zero can be shown. In turn, these results allow deriving the behavior of the entropy near absolute zero, as has already been shown previously. The point of view is the phenomenological, macroscopic, and non-statistical one of classical thermodynamics.

Abstract: The cosmological constant problem—QFT vacuum energy exceeding observations by \( 10^{120} \)—remains unsolved without fine-tuning or anthropics. We present a semiclassical determination of \( \Omega_\Lambda \) from Standard Model field content on a spherical cosmological horizon. Under a small set of discrete modeling assumptions (M1–M4), we project Standard Model fields onto the monopole (\( \ell = 0 \)) block of a spherical horizon at radius \( R \sim H_0^{-1} \), apply Kubo-Martin-Schwinger (KMS) thermal weighting at the Gibbons-Hawking temperature \( T_{\mathrm{GH}} = \hbar c/(2\pi k_{\mathrm{B}} R) \), and use symmetry-fixed greybody factors. All boundary terms vanish by gauge/color/parity symmetries, with a geometric heat-kernel correction for bosons. The calculation yields a dimensionless loading \( \Delta^* = 17.46 \), which maps to \( \Omega_\Lambda = \Delta^*/(8\pi) = 0.695 \pm 0.008_{\mathrm{th}} \) via a geometric normalization fixed by the causal diamond solid angle. Comparison with DESI 2024 + CMB data \( \Omega_\Lambda^{\mathrm{obs}} = 0.693 \pm 0.005 \) shows agreement within \( 0.2\sigma \). Every coefficient derives from Standard Model structure, spherical geometry, or thermal physics—no uncanceled UV divergences or fitted continuous parameters under assumptions M1–M4.