Physical Sciences

Abstract: Despite the tremendous progress of quantum physics, there is a widespread belief that something is missing in our knowledge. A belief that maybe the answer is not in more abstractions, extra dimensions, or higher mathematics. I suggest we reexamine our foundational assumptions. First off, mechanics – classical or quantum – assumes a reality of existing objects in space bearing properties, including kinetic energy (KE). Fudges to “existing” (being massless or mathematical) and to “space” (e.g., Hilbert) have only taken us so far. I submit that the essence of radiation (the photon) is immaterial occurrence. Why do we force it to obey a model (mechanics) based on existing constituents? Second, I contend that quantum pioneers were too quick to accept – and we have been too lazy/busy to question – the equivalence of photon momentum with rest mass momentum. We actually don’t understand momentum.

Abstract: Indoor badminton venues are common mass-fitness spaces in China, but their acoustic environment remains underexamined relative to lighting, thermal comfort, and functional facilities. This study uses grounded theory to examine how users perceive acoustic conditions within the broader experience of indoor badminton venues. A total of 4,721 raw online reviews for seven purposively selected venues in five Chinese cities were collected, and 3,937 valid reviews remained after preprocessing. A hybrid text-processing procedure combining DeepSeek-V3-assisted term pre-screening and Python jieba segmentation identified 74 core high-frequency terms; all grounded-theory coding was conducted manually in NVivo 15. Open, axial, and selective coding generated 32 initial categories, 6 main categories, and an Indoor Badminton Venue User Experience Perception Model. Acoustic-related categories were then extracted to construct an Acoustic Environment Perception Mechanism sub-model. The results show that noise level was directly mentioned in only 45 reviews but was indirectly embedded in sport atmosphere, time-based flow, and user experience, indicating a latent perceptual role. Moderate sound may be interpreted as a vibrant sport atmosphere, whereas crowd overload and reverberant spatial conditions may shift perception toward chaotic noise. The findings provide qualitative evidence for integrating user-centered acoustic considerations into the design and operation of mass-leisure sports venues.

Abstract: Low-field nuclear magnetic resonance (NMR)-based stimulation is an emerging non-invasive biophysical approach for tissue modulation. Unlike optical or mechanically mediated modalities, its magnetic-field components are less constrained by tissue depth, enabling distributed exposure of deep anatomical structures. This review examines its physical principles, focusing on cyclic adiabatic passage, longitudinal relaxation time (T1), and how field parameters and tissue relaxation properties shape the spatial and temporal distribution of the applied perturbation. Clinical studies indicate a favorable safety profile together with reported improvements in pain, physical function, quality of life and related outcomes across several musculoskeletal indications, while experimental studies demonstrate modulation of inflammatory signaling, mitochondrial function, metabolism and redox-sensitive pathways. Two major mechanistic questions are identified: how a relaxation-weighted perturbation, potentially shaped by extracellular, pericellular or matrix-associated tissue properties, is transmitted to intracellular signaling pathways, and how weak non-thermal perturbations are amplified into specific biological responses. A multi-level framework is proposed to investigate how physical perturbations are distributed in tissue, transmitted to intracellular pathways, shaped by cellular state and amplified into measurable biological responses. Low-field NMR-based stimulation represents a physically plausible but mechanistically unresolved modality whose further development will depend on integrating magnetic resonance physics with systems-level biology.

Abstract: Physical AI requires machines to sense, decide and act under tight constraints of energy, latency, safety and robustness. A fly escaping an approaching hand captures the core principle: a fast sensor-action reflex acts before full deliberation, while higher neural resources remain available for richer behavior. This Perspective proposes a layered Reflex-Policy architecture in which reflex layers execute fast, local, ADC-light actions near sensors and actuators, while policy layers perform slower learning, planning, optimization and rule updates. The two are mutually protective collaborators: policy layers define safe operating envelopes, while reflex layers shield policy processors from high-frequency events and avoidable data floods. We position binary spintronic MTJ crossbars as a plausible technology path for low reflex layers, while distinguishing today's MRAM/eMRAM technologies from the proposed reflex-layer crossbar module, which remains an architectural research target. The contribution is a system-integration framework: intelligence is distributed along the sensing, energy, storage and action chain, and each event is assigned to the lowest sufficient layer. We formalize Energy Returned on Invested Energy for Embodied Intelligence (EROIE), compare the framework with related architectures, and state its limitations and validation needs.

Abstract: Quantum tunneling is conventionally described using the stationary Schrödinger equation with an externally imposed potential barrier. In this work, we present a dynamical formulation of quantum tunneling in which the barrier is modeled as a structured medium possessing quantized internal modes that interact coherently with an incident electron. Using the Heisenberg operator formalism and a second-quantized representation of the barrier medium, we derive coupled dynamical equations governing the electron–barrier interaction. Under a continuum-mode and mean-field approximation, the collective response of the barrier modes generates an effective potential that reproduces the conventional rectangular barrier model and the standard tunneling transmission probability obtained from the Schrödinger equation. Within this framework, a tunneling traversal time is naturally defined from the dynamical evolution of the electron and is shown to depend on the barrier width, barrier height, and incident electron energy. Numerical simulations illustrating the transmission probability and tunneling-time behavior are presented. The results provide a complementary microscopic interpretation of tunneling processes in structured quantum media and may be relevant to nanoscale transport, photonic barriers, and coherent quantum devices.

Abstract: In-use heat transfer coefficient (HTC) measurements are useful for retrofit evaluation, heating system sizing, and thermal performance assessment in occupied homes. Quantifying the variance in the in-use HTC when, necessarily, utilising a range of assumptions and simplifications is therefore crucial, and also critical for further method development. Two empirical sensitivity analyses were used to explore how changes in commonly assumed in-use factors affect HTC estimates in occupied homes. The factors investigated were measurement uncertainty, solar gains, metabolic gains, boiler efficiency, water use, party wall heat transfer, and ventilation rate - parameters that are impractical or impossible to routinely measure, and as such default values are generally adopted. The sensitivity analyses used data from seven occupied homes and a single, common, HTC estimation method. Input distributions for each factor were derived from available data and current assumptions. A local sensitivity analysis examined how changes in each input affect the HTC and a global analysis quantified the contribution of the inputs’ variance to the HTC’s variance. Conducting parallel analyses enabled a more complete picture to be obtained, and the alignment of the two approaches provided confidence in their results. The factors with the greatest overall effects on the HTC were ventilation and party wall heat transfer; however, this was not the case for every home. In particular, HTCs from homes with higher occupancy exhibited stronger HTC sensitivity to metabolic gains and water use. The use of real data from occupied homes enables the results to be applicable to typical imperfect datasets. The results will inform future applications of in-use HTC measurements and methods for determining their uncertainty. Further work expanding this analysis to a larger dataset with more building typologies, and gathering data to define the sensitivity analysis more accurately would strengthen these conclusions.

Abstract: One of the bottlenecks in realizing all-optical computing is the lack of on-chip all-optical logic devices that combine compact, low-loss, and highly robustness. Valley photonic crystals (VPCs) have become an important solution for realizing such devices, relying on the excellent transmission characteristics of topological valley states. However, existing structures still face issues such as limited design flexibility. In this paper, a high-performance topological all-optical logic device based on VPCs consisting of circular ring dielectric columns is designed and demonstrated. By introducing the inner radius as an independent design parameter, we construct a new type of VPC and systematically investigate its influence on the photonic band gap. Based on this, we design a beam splitter with high operational bandwidth and low insertion loss (<0.5 dB), and then realize fundamental OR and XOR logic gates, achieving extinction ratios of 18.9  dB for the OR gate and up to 44  dB for the XOR gate at an operating frequency of 193.5  THz. The platform also supports the NOT gate and, through cascading, can implement more logic functions such as AND gate.

Abstract: The spicules, flares, any plasma jets, and stellar lightning participate in the coronal heating dynamics of the Sun and Stars. The essential concept of the coronal heating problem in understanding how the upper atmosphere of stars and the Sun is heated to multi-million-degree temperatures, and its lower zone, the photosphere and chromosphere, still at 5000 K or 10000 K, remains one of the great unsolved issues in the history of astrophysics. Magnetic field dominates coronal heating dynamics since Magnetic pressure is higher than the thermal pressure of ions and particles. This tussle and equilibrium between them enhances the surface temperature and brightness of the star's outer atmosphere. The speed and temperature of the energetic particles in the plasma jets and stellar lightnings of the stars, the surface temperature, and the luminosity of stars could be determined mathematically. The particles with higher speed, momentum, and maximum equivalent temperature can leave the surface of a star with a speed higher than the escape velocity. The particles with a minimum speed and lower temperature in the plasma jets and spicules may fall back to the surface of stars as coronal rain. Particles in the Coronal mass ejection have enough energy and speed to escape from the external surface of stars as a solar wind. Plasma Jets and stellar lightning are energetic particles and ions that come out rapidly from the interior shells of the Sun and Stars to enhance coronal heating dynamics. Plasma jets and stellar lightning emerge vertically from the lower shells of stars, cause violent turbulence on their surfaces in the photosphere and chromosphere, and are involved in the coronal heating dynamics of the stars and the Sun. The central temperatures of stars range from 20 million kelvins to 3 billion kelvins due to nuclear fusion processes, causing ions and energetic particles to form powerful plasma jets, stellar lightning, nanoflares, spicules, solar wind, and coronal mass ejections on stellar surfaces. The thermal pressure prevailed over the magnetic pressure and increased the speed of energetic particles to leave the exterior surface of stars. The lifetime of stellar lightnings is a few seconds and difficult to detect with present technology, but the lifetime of spicules, stellar flares, and coronal loops is extended to several minutes and days. Maximum plasma jets and stellar lightnings may be displayed on the surface of a massive star due to the fusion of heavy elements in its fusion ball in the core, typically Oxygen, silicon, germanium, and manganese.

Abstract: We present a unified Rubik’s tetrahedral spinor geometry that accounts for the charged-lepton and neutrino mass hierarchies through discrete internal curvature. In this framework, fermion masses arise from activation of Hermitian bilinear curvature channels within a tetrahedral spinor manifold. The mass spectrum of the k-th generation follows a simple logarithmic mass law, ln⁡(m/m₁)=8 ln⁡k, or more precisely, with extra correction terms as ln⁡(m/m₁)=8 ln⁡k+ Ak² (k-1)+Bk³ (k-1). The mass law contains a fixed ladder coefficient of eight, corresponding to eight curvature channels, which can be visualized as a self-similar fractal Rubik’s tetrahedron, and reveals an invariant combination A_l+B_l=-9/4 (relative error < 10^-6%), consistent with quadratic spin contraction. In contrast, neutrino masses emerge from cyclic pseudo-temporal mixing of an internal triplet, producing a distinct invariant A_ν+B_ν=-4√3 (relative error0.003%). The √3 factor arises naturally from triplet normalization rather than parameter tuning. The two sectors thus reflect different curvature regimes within a common spinor structure. These results suggest that generational hierarchy encodes discrete geometric invariants, providing a curvature-based origin of lepton mass structure beyond phenomenological Yukawa parametrization.

Abstract: The standard interpretation of quantum measurement on entangled systems holds that measuring one particle nonlocally collapses the wavefunction of its spacelike-separated partner. We argue that this conclusion rests on a false presupposition: that subsystems of entangled systems possess independent ontic states. If the global wavefunction is the sole ontic object (ψ-ontic holism), then for entangled systems there is no “state of B” to be affected by measurement at A. The reduced density matrix of a subsystem, while operationally useful, is not ontologically real for non-factorizable states. Measurement is a local dynamical process — concretely modeled by continuous spontaneous localization (CSL) — that destroys one local wavefunction component at the measurement site. The global state factorizes as a consequence, and subsystem ontology emerges for the first time. The transition of the distant particle’s reduced density matrix from mixed to pure reflects this emergence of separability, not a physical change at the distant location. We show that this framework is consistent with no-signaling, with the contextuality required by the Kochen–Specker and GHZ theorems, and with the local measurement axiom (Postulate M) proposed in a companion paper. Bell’s theorem does not force nonlocality upon our framework because it presupposes outcome determinism — the assignment of definite values to observables prior to measurement — which several quantum mechanical theorems and our ψ-ontic ontology explicitly deny. Decoherence, which is ubiquitous in nature, provides the mechanism by which the global wavefunction factorizes and classical separability emerges. The apparent nonlocality of quantum mechanics is thus reinterpreted as nonseparability: the fundamental ontology is holistic, but the dynamics are local.

Abstract: Recently, several studies have investigated the validity of General Relativity’s predictions. Gravitational waves provide an ideal probe for testing the theory in the strong field regime. In this work, we consider a class of modified-gravity theories, specifically f(R), and scrutinize their predictions for the gravitational-wave emission from the coalescence of two astrophysical compact objects. We also assess the impact of next-generation gravitational-wave detectors on the ability to test these extensions of General Relativity.

Abstract: Given that red blood cells (RBCs) are the most abundant cells in blood, their morphology and mechanics strongly affect blood rheology. Furthermore, changes in the physiological functions and health status of an organism can also affect RBC mechanics. Therefore, understanding the mechanical properties of RBCs holds substantial research value in the biomedical field. Optical tweezers (OT) technology has become a crucial method for measuring and analyzing the mechanical properties of RBCs, owing to their unique advantages such as non-contact manipulation and piconewton-level force sensitivity. This review first outlines the basic mechanical properties of RBCs, the mechanical sensing principles of optical tweezers, and their basic manipulation modes. It then focuses on the measurement and application of key mechanical parameters, such as the deformation index and shear modulus. Furthermore, the review also covers the integration of optical tweezers with Raman spectroscopy, fluorescence, and microfluidics. These combined approaches allow for the simultaneous acquisition of mechanical and molecular data, dynamic monitoring of mechanical state changes, and analysis of external stimuli and physiological mechanisms, thereby supporting disease diagnosis, drug efficacy evaluation, as well as artificial blood quality assessment.

Abstract: In this study, we present a thermal-aware design of a compact hybrid plasmonic grating (HPG) TE-pass polarizer on X-cut lithium-niobate-on-insulator (LNOI) for fiber-optic gyroscopes (FOGs). In a three-dimensional simulation, the optimization of the trapezoidal sidewall angle (θ = 78°) and the thickness of the Ag grating (13 nm) yield a polarization extinction ratio of 36.2 dB at 1550 nm (with a peak of 41.4 dB at 1548 nm) within a sub-10 μm grating length. This represents a ~3–8 dB improvement over prior LNOI HPG polarizers at the same footprint. A multiphysics thermo-optic analysis over the wide industrial FOG envelope (from −45 to +85°C) demonstrates that the operating-wavelength polarization extinction ratio remains within the range of 24.7–36.2 dB across the entire 130 K span (worst case 24.7 dB at −25°C), constrained solely by a modest 10 pm/°C Bragg detuning stemming from the pronounced (~5) thermo-optic anisotropy of LN. The insertion loss exhibits a negligible drift of merely 0.73 dB. A fabrication-tolerance study identified the Ag thickness as the predominant budgetary constraint (±1 nm tolerance, PER dropping ~10 dB at the resonance edge), while the ridge width and oxide buffer demonstrated comparatively greater flexibility. The device, therefore, fulfills the criteria for FOG-grade polarization suppression across the majority of the operational temperature range. The −25 °C point is established at the 25 dB threshold, thereby providing concrete design guidelines for ensuring environmentally stable on-chip polarization control on LNOI.

Abstract: The article examines the origins of modern mathematical physics in Kyiv and provides an overview of M. Bogolyubov’s manuscripts produced at the Institute of Mathematics.

Abstract: High energy physics software uses reference particle data at all stages of modeling, reconstruction, and analysis. While programmatic access to Particle Data Group data is available through REST and Python-based solutions, there has been no native Kotlin implementation for the Java Virtual Machine ecosystem until now. This paper presents KParticle, a Kotlin-based solution for providing structured access to particle reference data using the SQLite database distribution. The system uses a multi-tiered architecture that separates client applications from database-specific implementation details, ensuring modularity and scalability. KParticle is suitable for integration into modeling environments, data analysis pipelines, validation tools, and machine learning applications, improving the integration of particle reference information.

Abstract: A local finite-carrier theorem is proved for primitive optical Codazzi defects. After real blow-up of a codimension-three core, the resolved optical link is $\mathbb{CP}^1$, and the primitive transverse class gives $L_\Gamma\simeq\mathcal O(1)$. The positive equivariant Dirac index is then the Borel-Weil tower. For any natural scalar-sector transverse source of order $\leq2$, after the scalar singlet is separated, the non-scalar associated-graded source has only the $V_1$ and $V_2$ types. When both non-scalar channels are present and separated at principal order, Toeplitz visibility gives their first separated supports as $E_2$ and $E_3$, hence the minimal separated carrier $E_3\oplus E_2$. After the link-equivariant selection has fixed the blocks, the selected blocks are read as Hermitian carrier spaces. With the unimodular top-form constraint this gives the compact basis group $S(U(3)\times U(2))$ and the standard one-generation exterior package. The same primitive class has a mod-three projective-color shadow, giving a central $\mathbb Z_3$ family-response torsor. An Alena-type current-residual collar is used as a sufficient realization of the source hypotheses. In the gauge-branch reading, the same collar gives a conditional self-description mechanism in which the gauge-side stress supplies the separated current and stress-response channels. Flavor, thresholds, and running remain closed spectral data.

Abstract: The transits of Venus occur in couples each 105/122 years: the observed ones are 1639; 1761-1769; 1874-1882, and 2004-2012. The next couple will be in 2117-2125. We would need all four contacts to determine the solar diameter accurately. The black-drop phenomenon blurred always the internal contacts, so we developed a parabolic analysis of the chords drawn by the disk of Venus on the solar limb. The extrapolation to zero gives the contact timings. We tested this method with some high quality images obtained in 2004 and 2012, and we applied it to the observations of 2012 in visual band (Huairou Solar Observing Station, hazy weather) and H-alpha (Shen Zen Astronomical Observatory). To exclude a reduction of the measured diameter by the haze, we made two series of measures at the Clementine Gnomon (Rome) and at PHYSIS telescope (Rome), under various sky transparencies and with diffraction limited instruments. The haze, and the low altitudes above the horizon reduced the accuracy at all first contacts examined, without changing the solar diameter. Our measures obtained in China during the transit of 2012 yielded a photospheric radius R_¤P=959.33”±0.06”, based on 76+75 images diffraction limited; compatible with the chromospheric radius measured at the base of the spiculae was R_¤C=959.78”±0.11”, relying on 7+5 diffraction-limited series of images.

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: This paper employs the Lie group method of invariants to re-investigate the domino toppling problem. By defining an anisotropic scaling group distinguishing horizontal propagation from vertical gravitational fall, we rigorously derive the universal scaling law \( v=\lambda \sqrt{\frac{g}{h}} f(\frac{\delta}{\lambda}) \) through both finite group transformation and infinitesimal generator approaches. Curve fitting yields the approximate power law \( v\sim \sqrt{\frac{\delta \lambda }{h}g} \). The Lie group decoupling reveals that the speed is governed by an effective dynamical length \( L_{eff} = \delta\lambda/h \) and is independent of domino width. Furthermore, we clarify that the power-law exponent \( \alpha \approx 1/2 \) corresponds to a complete scaling symmetry in the ideal frictionless limit. The introduction of friction breaks this symmetry, causing \( \alpha \) to fluctuate around \( 1/2 \), which is interpreted from the perspective of symmetry breaking.

Abstract: The Bohr radius is normally presented as a non-relativistic length scale. Less widely discussed is that, in the second part of his 1913 trilogy, Bohr briefly indicated how the radius formula could be modified when the orbital velocity is not negligible compared with the speed of light. In this paper, we revisit that overlooked prescription and show that replacing the electron rest mass by the Lorentz-factor-adjusted mass term leads to a relativistic Bohr radius a_(0,r) = a₀ √(1 -α²) = (λ̅_e√(1 -α²))/α for hydrogen, and to a^Z_(0,r) = a₀/Z √(1- Z²α²) for a hydrogen-like one-electron ion. The central result is that this semi-classical expression is not merely an ad hoc relativistic contraction: under the assumptions of a point nucleus, infinite nuclear mass, and a one-electron Coulomb field, it is exactly identical to the most probable radius obtained from the Dirac 1s_1/2 radial probability density. This identification appears to be the first explicit demonstration that Bohr’s historical relativistic prescription selects the Dirac most-probable radius, rather than the Dirac expectation value ⟨r⟩D. We emphasize the important distinction between a most-probable radius and a mean radius: even in the non-relativistic Schrödinger 1s state, the most-probable radius is a₀/Z, whereas the expectation value is 3a₀/(2Z) and is therefore larger by a factor of 3/2. For hydrogen the relativistic correction to the most-probable radius is only 1.40898891811 × 10⁻¹⁵ m, or 0.0026626%, but the result is conceptually significant because it links Bohr’s semi-classical radius, the relativistically contracted reduced Compton wavelength, and the Dirac-Coulomb ground-state probability maximum in one compact formula. We also provide numerical values for hydrogen-like ions and explain why these smooth one-electron Dirac radii should not be confused with expectation values or with empirical radii of neutral many-electron atoms, which can vary non-monotonically across the periodic table.