Abstract:

This paper presents a revival of FORTRAN 66 code which calculates flow through curved pipes. Results from the code were originally presented in [Greenspan, D. Secondary flow in a curved tube. J. Fluid Mech. 1973, 57, 167-176]. The coupled non-linear system of partial differential equations was solved numerically using a finite difference method. We demonstrate a step-by-step code revival process and compare original (coarse) results to updated (fine) solutions. Both the structure of streamwise (primary) and secondary flows are covered. The purpose of our paper is to make the code available as modern Fortran for the scientific community. The code runs quickly on modern hardware architectures and enables fast understanding of the physical effects included.

Abstract: Among the theoretical problems with the prevailing theory of cosmology, Lambda Cold Dark Matter (λCDM), the most serious appears to be the twofold problem with the cosmological constant lambda: Dark Energy and Hubble Tension. Despite a two-decade search for systematic errors in astrometry the problems have not been resolved. This paper posits a potential source of error that may have affected astrometry related to the current and past measurements of lambda.

Abstract:

Inspired by the author 's Riemann conjecture, this paper attempts to solve the contradiction between four dimensional spacetime and quantum mechanics in physics. Guided by Euler 's formula, two important ideas of collision and vibration are introduced. The document deeply discusses the relationship between substance dimension and energy, including the stability and change of dimension, the relationship between energy and substance, the relationship between time and dimension and so on. Through detailed assumptions and explanations, this paper provides a new perspective for us to understand the complexity of the substance world. It mainly introduces how substances of different dimensions interact, the generation and transformation of energy, and the influence of dimensional changes on substances. The following is a summary of the core content of the paper :substance dimension and energy, the influence of dimension change, the stability and change of dimension, the relationship between gravitational field and dimension, time and dimension, and the realization of dimension change.

Abstract: This study examines the dynamics of two spheres falling independently in a viscous fluid, highlighting conditions under which a lighter sphere can achieve a higher velocity than a heavier one. Through theoretical modeling and simulations, the motion of spheres with varying densities and radii, released simultaneously in a uniform viscous medium, was analyzed. The investigation considers gravitational, buoyant, and drag forces, with the spheres moving under identical initial conditions and without mutual interaction. The results confirm the well-established case where the heavier sphere exhibits a greater terminal velocity. However, an intriguing phenomenon is identified: under specific conditions, a lighter sphere can surpass its counterpart in terminal velocity. Additionally, when spheres of equal weight are compared, the denser sphere consistently attains a higher terminal velocity. The study reveals non-trivial time-dependent acceleration patterns, with alternating dominance between heavier and lighter spheres before terminal velocities are reached. Furthermore, the order of impact with the ground is shown to depend on the release height, illustrating a complex interplay of forces. These findings offer novel insights into fluid dynamics, with implications for education and engineering applications.

Abstract: This research answers the knowledge gap regarding the explanation of the quantum jump of the electron. This scientific paper aims to complete Einstein’s research regarding general relativity and attempt to link general relativity to quantum laws.

Abstract: We present a framework extending the Quantum Memory Matrix (QMM) principles, originally formulated to reconcile quantum mechanics and gravity, to the domain of electromagnetism. In this discretized space–time approach, Planck-scale quantum cells act as memory units that store information via local quantum imprints of field interactions. By introducing gauge-invariant imprint operators for the electromagnetic field, we maintain unitarity, locality, and the equivalence principle while encoding electromagnetic data directly into the fabric of space–time. This construction ensures that black hole evaporation, including for charged black holes, respects unitarity, with initially hidden quantum information emerging through subtle, non-thermal correlations in the emitted radiation. The QMM framework also imposes a natural ultraviolet cutoff, potentially modifying vacuum polarization and charge renormalization, and may imprint observable signatures in the cosmic microwave background or large-scale structures from primordial electromagnetic fields. Compared to other unification proposals, QMM does not rely on nonlocal processes or exotic geometries, favoring a local, covariant, and gauge-invariant mechanism. Although direct Planck-scale tests remain challenging, indirect observational strategies—ranging from gravitational wave analyses to laboratory analog experiments—could probe QMM-like phenomena and guide the development of a fully unified theory encompassing all fundamental interactions.

Abstract:

Owing to the global incentives targeted towards the advancement of semiconductor science and technology, the importance of a reliable method for the fundamental characterization of the interface between metals and low-dimensional semiconductors cannot be emphasized enough. For decades now, X-ray photoelectron spectroscopy (XPS) has been relied upon rather heavily when it comes down to investigating the band-bending, and hence the likelihood of a Schottky-barrier formation, at the resulting interfaces. However, the true extent to which the usually reported analyses of XPS measurements, attempting to unravel the true nature of metal–semiconductor interfaces, can be taken without a grain of salt is questionable at best. Therefore, in this article, a conceptual advance aiming to alter the status quo pertaining to the use of XPS for the aforementioned studies is presented.

Abstract: In this work, we present a graphene-based photodetector specifically engineered to op-erate at a wavelength of 1310 nm. The device leverages the SPARK effect, previously investigated only at 1550 nm. It features a hybrid waveguide structure comprising hy-drogenated amorphous silicon, graphene, and crystalline silicon. Upon optical illumi-nation, defect states release charge carriers into the graphene layer, modulating the thermionic current across the graphene/crystalline silicon Schottky junction. The photo-detector demonstrates a peak responsivity of 0.3 A/W at 1310 nm, corresponding to a noise-equivalent power of 0.4 pW/Hz¹/². The experimental results provide deeper insights into the SPARK effect by enabling the determination of the efficiency × lifetime product of carriers at 1310 nm and its comparison with values previously reported at 1550 nm. The wavelength dependence of this product is analyzed and discussed. Additionally, the response times of the device are measured and evaluated. The silicon-based fabrication approach employed is versatile and does not rely on sub-micron lithography techniques. Notably, reducing the incident optical power en-hances the responsivity, making this photodetector highly suitable for power monitoring applications in integrated photonic circuits.

Abstract: Today’s physics describes nature in “empirical concepts” (based on observation), such as coordinate space/time in special relativity (SR), curved spacetime in general relativity (GR), and wave/particle. There are coordinate-free formulations of SR/GR, but there is no absolute time in SR/GR and thus no “holistic view” (universal for all objects at the same instant in time). I show: Euclidean relativity (ER) provides a holistic view by describing nature in “natural concepts” (immanent in all objects). Proper space/time (pure distance) replace coordinate space/time. Curved worldlines in flat Euclidean spacetime (ES) replace curved spacetime. “Wavematters” (pure energy) replace wave/particle. Any object’s proper space d₁, d₂, d₃ and its proper time τ span d₁, d₂, d₃, d₄ (ES), where d₄ = cτ. The invariant is absolute, cosmic time θ. All energy moves through ES at the speed c. An observer’s view is created by orthogonally projecting ES to his proper space and to his proper time. For each object, there is a 4D vector “flow of proper time” τ. Information is lost if the 4D vector τ is ignored, as in SR/GR. ER solves the Hubble tension. Also, ER declares dark energy and non-locality obsolete. I conclude: (1) Acceleration rotates an object’s τ and curves its worldline in flat ES. (2) Information hidden in τ solves 15 mysteries. (3) Different concepts disable a unification of SR/GR and ER. Either scope is limited. We must not apply SR/GR but ER whenever τ is crucial (high-redshift supernovae, entanglement). We must not apply ER but SR/GR whenever we use empirical concepts.

Abstract: Within the self-consistent Maxwell-Pauli theory, a nonlinear Schrödinger equation with a short-range compensating field is derived. Stationary and non-stationary solutions of the obtained nonlinear Schrödinger equation for the hydrogen atom are investigated. It is shown that spontaneous emission and the associated rearrangement of the internal structure of the atom, which is traditionally called a spontaneous transition, have a simple and natural description within the classical field theory without any quantization and additional hypotheses. The solution of the nonlinear Schrödinger equation showed that, depending on the frequency of spontaneous emission, the compensating field behaves differently. At relatively low frequencies of spontaneous emission, there is no radiation (waves) of the short-range compensating field and this field does not carry away energy. In this case, the damping rate of the spontaneous emission coincides with that obtained in quantum electrodynamics (QED). At relatively high frequencies of spontaneous emission, radiation (waves) of the compensating field arises, which, along with electromagnetic radiation, carry away some of the energy. In this case, the damping rate of the spontaneous emission is greater (up 1.5 times) than that predicted by QED.

Abstract: This paper presents a critical review of existing Zitterbewegung models of the electron, assessing their compatibility with Dirac theory, special relativity, and observed particle physics data. We highlight the strengths and limitations of each model, while also introducing a perspective of the electron based on field dynamics rather than particle concepts. Our aim is to determine whether fundamental properties of the electron—such as spin, charge, mass, and relativistic behavior—can be derived from first principles.

Abstract: This research investigates the structural, electronic, mechanical, and vibrational properties of double half-Heusler compounds with the generic formula Ti2Pt2ZSb (Z = Al, Ga, and In) using density functional theory calculations. The generalized gradient approximation within the Perdew-Burke-Ernzerhof functional was employed for structural optimization and the hybrid HSE06 functional for electronic properties. Our results demonstrate that these compounds are energetically favorable, dynamically and mechanically stable. Electronic structure calculations reveal that Ti2Pt2AlSb double half-Heusler compound is a non-magnetic semiconductor with an indirect bandgap of 1.49 eV, while Ti2Pt2GaSb and Ti2Pt2InSb are non-magnetic semiconductors with direct bandgaps of 1.40 eV. The alloys exhibit low lattice thermal conductivity (2.35–2.66 W/mK) and high melting temperature (1211–1248 K), making them promising candidates for high-technological applications. Further performed analysis, including phonon dispersion curves, electron localization function (ELF), and Bader charge analysis, provides insights into the bonding character and vibrational properties of these materials.

Abstract: We model the energy depletion of light from a distant object with two components: loss in photon rates (number of photons) and loss per photon particle. We model the rate loss based on intergalactic extinction, which, unlike extinctions within our local group of Milky Way, LMC and SMC, has not been previously accounted for. Ignoring intergalactic extinction results in overestimation of cosmic distances with standard distance moduli. Such extinction effect is more profound on large scales (Gpc) that we have only started to observe today. We then apply the tired light model for energy loss (redshift) per photon. These two model components are mathematically very simple, leading to a new equation between luminosity distance and redshift. The model performed equally well as ΛCDM with Pantheon+ SN data while outperformed it with deep-field galaxy angular size test. The main implications of the intergalactic extinction model are two-fold: it identifies a major bias in distance measurements based on standard candles; it is also a key missing piece for static universe models to offer as viable alternatives to ΛCDM. Thus, the model has further implications on the interpretation of cosmic redshift, Hubble’s law, the Hubble constant, Hubble tension, and universe history.

Abstract: This paper presents results of complimentary experimental (by electron microscopy, X-ray diffraction, diffuse reflectance, photoluminescence (PL) and FTIR spectroscopy) and computational (by molecular dynamics and DFT-based electronic structure methods) studies of oxide glasses of xP2O5-yMoO3-zBi2O3-(1-x-y-z)K2O system and glass ceramics based on them (crystal @glass), where the KBi(MoO4)2 complex oxide is the crystal component (KBi(MoO4)2 @glass). The behavior of the observed PL characteristics is analyzed in synergy with results of calculations of their atomic structures and changes in the oxygen environment of bismuth atoms during the transition crystal interphase glass. It has been shown that the optical absorption and PL characteristics of such systems are largely determined by content of Bi2O3 and MoO3 oxides in the initial charge, and by content bismuth ions in different charge states which exist in the produced glass and glass ceramics. It was found that the blue PL (spectral range 375 – 550 nm) of both glasses and glass ceramics originates from radiative transitions 3P1 1S0 in bismuth ions Bi3+. The yellow-red PL (range 550 – 850 nm) should be mainly associated with the luminescence of bismuth ions in lower charge states, Bi2+, Bi+ and Bi0. The thickness of the interphase layers of glass ceramics is estimated to be 1.5-2.0 nm. It has been shown that the changes in the spectra of optical absorption and PL / PL excitation of the glass ceramics occur due to the decrease in the number of oxygen atoms in the nearest surrounding of bismuth ions in the interphase region and these changes can be used for spectral probing of the formation and presence of interphase layers.

Abstract: This work presents a toy universe grounded in classical logic, elementary natural arithmetic, and a touch of topology. The universe’s space is modeled as a finite, closed, discrete 3-torus with an additional non-spatial dimension of a carefully selected size. Each point within this space contains a fixed-size string of two-state elements, each possessing an ontological character. A few recurring patterns are observed across these layers: one based on the Euclidean distance from a central point, the second following a sinusoidal bit mask relative to the same point, the third is a unique ray marking a privileged direction, and the fourth is a spiral path. These patterns are dynamic, relocating after interactions, but keeping most data the same, displaced relative to the other layers. Time in this universe is discrete. Electric charge is represented by a single bit, weak charge by two bits, and color charge by three bits. The linear motion dynamics of the universe are dictated by a radial line of bits, while the rotational one, by an orthogonal spiral of bits. Gravity is interpreted as an extension of the static electromagnetic force, where a certain charge combination acts as a graviton, resulting in a super deterministic model reliant on a few input parameters. The unit of energy is the layer itself, which groups as particles, either localized or similar to photons, using a fundamental collapse mechanism. Particles leave behind a trace of their momentum onto the lattice. This allows for interactions with subsequent waves, leading to patterns that resemble quantum self-interference and opening a door for falsifiability of the model. This constructive approach establishes a universal cellular automaton framework. Foundationally, this work is in line with 't Hooft's cellular automaton interpretation of Quantum Mechanics.

Abstract: In this paper, we attempt to interpret gravity by entropy. We first introduce generalized entropy, acceleration of its entropy and its partial entropy, and assume that generalized entropy can represent as a second-order polynomial by applying the idea of the logistic function to its entropy. Besides, we define the inverse of partial entropy as the gravitational potential. By applying these concepts, we attempt to explain that 1) gravity becomes constant values within small distance under certain conditions. It is possible that gravity has 5-states within small enough distance. There may exist anti-gravity which is the opposite of Newton's gravity among 5-states. Furthermore, within small distance, we show the possibility that the gravitational potential and the Coulomb potential can treat in the same way, that 2) the rotation speed of the galaxy does not depend on its radius if the radius is within the size level of the universe (The galaxy rotation curve problem), and that 3) the gravitational acceleration toward the center may change at long distance compared to Newton's gravity. We show that it becomes an expansion of Newton's gravity,and that the possibility of the existence of certain constants which controls gravity and the speed of galaxies, and that gravity may relate to entropy. It also describes the relationship between the Yukawa type potential and generalized negative partial entropy. Using equations proposed in this paper, it attempts to propose 11-types of forces (accelerations) including the gravitational acceleration g and compare the ratios of the fundamental 4-forces in nature (strong-force, electromagnetic force, weak-force, and gravity). Furthermore, it suggests that there may exist new forces, and that the gravitational constant G can fluctuate if entropy changes. Thermodynamics, quantum, gravity, electromagnetic and ecology may unify through entropy.

Abstract:

By incorporating quantum mechanics into gravitational theory through the so-called spacetime geometrization procedure that consists in applying the principle of least action alongside the covariance of quantum mechanical motion equations, we present a model that describes the gravitational behavior of antimatter whose existence is fundamentally rooted in quantum mechanics. This approach is based on the fact that the equivalence of gravitational and inertial mass in General Relativity can be replaced by the condition of covariance of classical equations of motion in curved spacetime. The findings show that even if the antimatter particles rest mass assumes negative values, the Newtonian gravity of point-like antimatter matter on macroscopic scale is attractive. The work also shows that the weak Newtonian gravity includes an additional quantum term that is inversely proportional to their mass and depending by the quantum mass density distributions. . The divergence of gravitational energy for infinitesimal masses may provide an explanation for the origin of field quantization in elementary particles and enforcing a discrete spectrum of elementary particle masses.

Abstract: The steady thermal model for conformal coating white LEDs is successfully developed to determine the temperature value in the package volume. The Matlab software (version 2017) and finite element method are utilized to solve the heat equation and visualize the temperature distribution, respectively. The thermal model is applied to study the temperature behavior of white LEDs under different injection currents of 50 mA, 150 mA, 250 mA, and 350 mA. The temperature value of each location is determined correspondingly by the temperature interpolation and comparing the color between color bar and color of the pcW-LEDs package structure. Beside, the effect of mesh size on the temperature simulation on the simulation result is also investigated. The result shows that the smaller mesh size provides higher resolution of temperature. The obtained result is meaningful for white LEDs thermal management to reduce the negative effect of heat during the operation process.

Abstract: The discrete version of the Biswas-Chatterjee-Sen model, defined on D-dimensional hypercubic Solomon networks, with 1≤D≤6, has been studied by means of extensive Monte Carlo simulations. Thermodynamic-like variables have been computed as a function of the external noise probability. Finite-size scaling theory, applied to different network sizes, has been utilized in order to characterize the phase transition the system presents in the thermodynamic limit. It has been noticed that the model undergoes a second-order phase transition for all considered dimensions. Despite the lower critical dimension being zero, this dynamical system seems not having any upper critical dimension, since the critical exponents change with D and go away from the expected mean-field values. Although larger networks could not be simulated because the number of sites drastically increases with the dimension D, the scaling regime has been achieved when computing the critical exponent ratios. However, logarithm corrections to scaling are present when analyzing the behavior of the critical noise probability.

Abstract: Despite the simplicity of flux collecting hardware, robustness to misalignments and immunity to seeing conditions, Intensity Correlation Imaging arrays using the Brown-Twiss effect to determine two-dimensional images have been burdened with very long integration times. The root cause is that the essential phase retrieval algorithms must use image domain constraints, and the traditional Signal-to-Noise calculations do not account for these. Thus the conventional formulations are not efficient estimators. Recently, the long integration times have been emphatically removed by a sequence of papers. This paper is a review of the previous theoretical work that removes the long integration times, making the Intensity Correlation Imaging, a practical and inexpensive method for high resolution astronomy.