Abstract:

We demonstrate that gravitational spin memory, conventionally regarded as a signature of massless spin-2 gravitons, can emerge from a purely scalar field theory when the scalar couples to matter through torsion-modified Riemann-Cartan geometry. Derivative Frequency Theory (DFT) posits gravitational phenomena arise from gradients of a massive scalar frequency field \( \omega(x) \) with inverse scale \( \mu^{-1} \sim 17 \) kpc determined from galactic rotation curves. We prove a general theorem: spin memory exists in any theory satisfying (i) asymptotic radiation, (ii) angular momentum sensitivity, (iii) parity-odd transport, and (iv) infrared memory kernel---independent of mediator spin. In DFT, chirality originates not from the scalar field itself but through its coupling to contorsion \( K^\lambda_{\mu\nu} = \xi\epsilon^\lambda{}_{\mu\nu\rho}J^{\rho\sigma}\partial_\sigma\omega \). The theory predicts distinctive Yukawa suppression of memory effects: \( \Delta\tau_{\text{DFT}}/\Delta\tau_{\text{GR}} \sim e^{-\mu D} \), leading to \( \sim \)45\% suppression for galactic LISA sources (\( \mu D \sim 0.6 \)) and complete suppression for extragalactic mergers (\( \mu D \gg 1 \)). We derive consistent predictions across scales: solar system tests satisfied (\( \Delta\gamma \sim 10^{-12} \)), flat rotation curves explained without dark matter, and cosmological perturbations nearly identical to \( \Lambda \)CDM at large scales. Weak equivalence principle violation is \( \mathcal{O}(10^{-47}) \), far below current sensitivity. The framework is falsifiable through three independent tests with clear timelines: galactic rotation curve morphology (JWST/SKA, 2025-2030), LISA memory measurements (2037-2040), and proposed LC oscillator experiments (1-2 years). DFT offers a minimal scalar alternative to GR that is testable, consistent with current data, and potentially transformative if confirmed.

Abstract: The rapid expansion of commercial human spaceflight is forcing a re-examination of how we decide who is “fit to fly” in space. For six decades, astronaut selection has been dominated by national space agencies using stringent, mission-driven criteria grounded in risk minimisation and long-duration operational demands. Contemporary standards such as NASA-STD-3001 and agency-specific medical regulations embed a philosophy in which astronauts are rare, heavily trained national assets expected to tolerate extreme environments with minimal performance degradation. In contrast, commercial operators aim to fly large numbers of spaceflight participants (SFPs) with highly heterogeneous medical and psychological profiles, under a US regulatory regime that emphasises informed consent and currently imposes very limited prescriptive health requirements on passengers. This article reviews the evolution and structure of traditional astronaut selection, outlines emerging approaches to screening and certify-ing commercial spaceflight customers, and explores the conceptual and practical gap between “selection” and “screening”. Drawing on agency standards, psychological se-lection research, and recent proposals for commercial medical guidelines, it proposes a risk-informed, mission-specific framework that adapts lessons from government as-tronaut corps to the needs of commercial spaceflight. We argue that future practice must balance inclusion and market growth with transparent, evidence-based risk manage-ment, supported by systematic data collection across government and commercial flights.

Abstract: We propose a conception of the Earth’s lithosphere as a geocosmic system composed of mobile lithospheric plates influenced both by external astronomical factors - such as solar radiation and tidal forces - and by internal planetary processes, including atmospheric and hydrospheric loading and mantle convection. It is shown that the annual periodicity observed in global seismicity has a distinctly astronomical origin, arising from the seasonal modulation of solar radiation between the Northern and Southern Hemispheres. The atmosphere may act as a mediator that transfers this annual signal to the tectonic plates. This new conceptual framework leads to hypotheses regarding a dynamic coupling between the atmosphere and the lithosphere. These hypotheses form the basis for the next stage of a research program aimed at understanding the Earth’s lithosphere as an integrated geocosmic system.

Abstract: The ionospheric conductivity is an important variable determined by the mobility of the charged particles and it also dependent of the plasma, neutral number of densities and charged particles. The ionosphere has advantages to absorb the harmful radiation from the Sun for all radio communications, navigation and surveillance transmissions through it. Temperature, cloudy and precipitations are the most factors to determine the wave mobility in the ionosphere region. The conductivity of the three selected districts depends on the altitude variation during day and night time. At altitudes of about 80 to 5000 km there is a flow of a number of current systems. This study was analysis the daily, monthly and seasonal contour variations of ionospheric conductivity in selected districts with their geographic latitude and longitude value. The wave conductivity was vary and increase throughly for the selected Models of Hall, Pederson and parallel conductivities with height and time variability of the ionospheric conductivities, cloudy and the precipitation was analysed with temperature variation for each districts.

Abstract: Astronaut selection is a foundational process for ensuring the safety, performance, and sustainability of human spaceflight missions. As exploration objectives expand beyond low-Earth orbit toward sustained lunar operations and future Mars missions, selection frameworks must identify individuals with advanced technical competence, physical robustness, psychological resilience, and strong team performance capabilities. This paper examines contemporary astronaut selection practices with a focus on the criteria, procedural stages, and comparative approaches employed by the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). Recent se-lection campaigns associated with NASA’s Artemis program and ESA’s astronaut re-cruitment initiatives are discussed. Particular emphasis is placed on the increasing in-tegration of quantitative human-factor metrics into selection decisions. The analysis highlights shared selection philosophies, institutional differences, and implications for long-duration exploration missions.

Abstract: Astronaut training has undergone significant transformation since the early days of human spaceflight, evolving in response to technological advances, changing mission objectives, and the increasing complexity of international cooperation. This paper provides a historical overview of astronaut training, tracing its development from the early Space Race era to the present day. It examines how initial training programs, largely focused on military pilots and short-duration missions, have expanded to encompass a broader range of skills, disciplines, and professional backgrounds. The paper compares astronaut training approaches across six major spacefaring entities: NASA (United States), Roscosmos (Russia), ESA (Europe), CNSA (China), JAXA (Japan), and CSA (Canada), highlighting both commonalities and differences shaped by national priorities, organizational culture, and mission requirements. In addition, the paper discusses the emergence of commercial human spaceflight and its impact on training philosophies, regulatory frameworks, and safety considerations. By outlining historical trends and current practices, this paper provides a comprehensive overview of astronaut training in the new era of spaceflight and identifies key factors influencing its continued evolution.

Abstract: This paper extends the substrate stress framework developed for Schwarzschild collapse to the Kerr geometry. The analysis begins with the exact Kerr Kretschmann scalar and expands all polynomial terms explicitly. A stress invariant is defined as σ(r, θ) = √|K(r, θ)|, and a critical value σc is interpreted as the threshold at which the continuum description fails; σc is treated as a phenomenological parameter that characterizes the substrate’s curvature tolerance. The condition σ(r, θ) = σc then determines the failure radius rc(θ), which depends on latitude due to the anisotropic curvature introduced by rotation. The resulting structure is oblate, with its largest radius near the equatorial plane and its smallest radius near the rotation axis. The Kerr ring singularity is never reached within this framework because the stress threshold is encountered at a finite radius. This produces a geometric picture of rotating collapse bounded by a stress-limited surface rather than a classical singularity, and the structure reduces to the Schwarzschild result when the spin parameter is set to zero. This construction yields a covariant framework for analyzing curvature-driven failure in rotating collapse and clarifies how spin modifies the internal geometric structure of black holes.

Abstract: The cosmic microwave background is often taken as definitive evidence for universal expansion. No static framework has yet reproduced its exact blackbody spectrum under known physical conditions. This study extends the companion paper Redshift Without Expansion by applying a frequency-independent redshift mechanism within a Liouville formulation. The kinetic redshift operator preserves a perfect Planck spectrum, maintains μ = 0, and yields T ∝ K−1 with an identical temperature–redshift relation T (z) = T0(1 + z) consistent with measurements from COBE and FIRAS. Photon number and energy densities evolve as ˙nγ = −3Heff nγ and ˙ργ = −4Heff ργ , where Heff = ˙K/K represents an effective Hubble parameter without metric expansion. The result establishes an observational degeneracy between kinetic redshift and geometric expansion while predicting a measurable secular temperature drift ˙T /T = −Heff ≈ −2.3 ×10−18 s−1. The framework provides a static, falsifiable pathway for examining the cosmic microwave background without reliance on expanding-space assumptions. The redshift kernel emerges from scalar field relaxation dynamics ¨Φ + Γ( ˙Φ − ˙Φ∞) = 0, with coupling Heff = g ˙Φ reproducing the required CMB temperature scaling to illustrative ∼ 0.1% precision for the example parameter set, and predicting Heff (z = 1100) ≈ 281H0, testable via high-redshift measurements.

Abstract: Lunar laser ranging (LLR) has currently achieved millimeter-level ranging accuracy, establishing itself as a powerful tool for testing general relativity, particularly the equivalence principle. However, atmospheric delay introduces spurious signals in LLR-based equivalence principle tests, significantly degrading parameter constraint precision. Through analysis of observational data from the Grasse station—which has contributed the most normal point data in recent years—we demonstrate that atmospheric delay may significantly affect the test of equivalence principle. Moreover, this paper provides a comprehensive analysis of how temporal and elevation-angle non-uniformity in atmospheric delay distribution affects equivalence principle tests. Simulation results demonstrate that fixing the elevation angle significantly enhances the precision of equivalence principle tests. Therefore, to achieve more stringent constraints, it is recommended to analyze segments from the long-term ranging archive that have minimal variation in elevation angle.

Abstract: This study advances the scientific program of Copernicus, Kepler, and Newton into the realm of tectonic processes. A generalization of Euler's rigid-body rotation theory to the case of an arbitrarily deformable spheroid is obtained. The generalized Copernican problem is solved: from the decomposition of motions into four elementary rotations to finding their compositions that describe complex trajectories of points on the Earth's surface. By analogy with Kepler's laws, the First Law of Tectonic Motion is established—a fundamental invariant of motion on a deformable spheroid asserting the preservation of conformal structure: the trajectories of tectonic motion are orbits of the Möbius group action. This approach creates a unified kinematic model linking astronomical variations in Earth's rotation with tectonic deformations, without invoking any hypotheses about the planet's internal structure.

Abstract:

The Dead Universe Theory (DUT) proposes that the observable universe is not an isolated, ever-expanding system emerging from a primordial singularity, but a thermodynamically decaying domain embedded within the collapsed geometry of a prior cosmological phase. In this framework, the visible cosmos constitutes a localized photonic anomaly—a transient luminous fluctuation—formed inside a large-scale structural black hole generated by the exhaustion of a former universe. Rather than ending in a Big Rip, Big Freeze, or Big Crunch, DUT predicts an asymmetric thermodynamic retraction in which usable energy is progressively depleted, driving the cosmos toward structural infertility and thermodynamic death on a timescale of order 10² Gyr (≈ 166 billion years). Beyond this horizon, matter persists only in fossilized configurations such as planets, stellar remnants, black holes, and extinguished galaxies, forming a “dead universe”. This thesis develops the mathematical, thermodynamic, and computational foundations of DUT and tests its consequences against current observational data. The work combines (i) entropic retraction equations with time-dependent curvature and entropy-derived cosmological terms, (ii) the Cosmic Fossil Record Method for dating the exhaustion of cosmic energy, and (iii) numerical simulations of galactic evolution under finite-energy and high-entropy constraints. These simulations reproduce quenching histories, fossil signatures, and an entropic horizon consistent with a structurally dying universe. Remarkably, DUT-based simulations anticipated several deep-field results from the James Webb Space Telescope, including compact galaxies at z > 13 and a population of Small Red Dots (SRDs) at z ≈ 15–20. The theory yields falsifiable predictions, such as a measurable excess of compact high-redshift systems, a mildly negative curvature parameter (Ωₖ ≈ −0.07 ± 0.02), and a declining structural natality of galaxies with cosmic time. By providing reproducible codes, explicit equations, and clear observational tests, DUT is presented as a coherent and testable alternative to ΛCDM for modeling cosmic chronology, entropy dynamics, and large-scale gravitational architecture.

Abstract: Hawking’s cosmology logically leads to an observed multiverse. This article proposes a novel hypothesis for the physical nature and existence of dark matter, derived from his cosmology This article argues it is a superposition of at least three 3-dimensional universes in a 4-dimensional space, of which two dimensions overlap with our universe. Nothing that could disturb the superposition exists outside it. This, with the dimensions of strings in String theory, explains why dark matter causes a linear decrease in gravity with distance to visible mass at large radii in galaxies. To support this, the visible matter distribution in the disks and bulges, calculated by the SPARC team, and the observed rotation velocities are used. Lelli and Mistele showed that the common way to project dark matter halos around galaxies cannot be valid. In this article it is shown a valid alternative is to model dark matter as three added wire-like masses in the centre of galaxies in General Relativity.Linear mass density is a key parameter and explains the weak effect in the centre of galaxies and the strong effect at larger distances as well as the rapid development of large galaxies in the early universe as reported by Labbé. A new prediction method for rotation velocities, that works at all radii in galaxies, is 19 % more accurate than MOND. In galaxy clusters the improvement of the predicted velocity dispersions compared with the Newtonian approach and with MOND is 44 to 57 % over a huge range of cluster masses.

Abstract: We propose a Chrono-Quantum Field Theory framework in which time is a complex scalar wave with phase and frequency but without intrinsic amplitude, while three-dimensional quantized space furnishes the amplitude through a spatial-amplitude operator. Writing t = iτ, the composite physical field Φ(x, τ) = A(x)Ψ_t(x, τ) intertwines an imaginary-time oscillation with a real spatial amplitude lattice. From a minimal postulate set we derive a covariant field equation, an effective proper-time law consistent with local Lorentz invariance, and a catalogue of falsifiable predictions. We then present a complete comparison with Einstein’s Special and General Relativity (SR/GR) across standard tests (time dilation, transverse Doppler, gravitational redshift, Shapiro delay, light bending, perihelion advance, frame dragging, binary pulsars, gravitational waves, GPS). Coarse-graining the temporal spectrum and spatial amplitude yields a positive effective vacuum term compatible with late-time acceleration (dark energy), while near-horizon behavior can be interpreted as a temporal-phase singularity. Finally, we outline a Chronodynamic Quantum Computer (CQC) that encodes information in temporal phase and uses the spatial lattice as amplitude memory, suggesting noise-shaping benefits and relativistic timing built-in. The paper closes with philosophical implications, discussion of limitations, and clearly targeted experimental pathways.

Abstract: This study investigates round-trip Earth–Mars–Earth missions during the 2031 opposition, applying a trajectory design framework derived from the early orbital configuration of asteroid 2001 CA21. Using Lambert-based analysis and JPL Horizons ephemerides, two optimized and dynamically consistent mission architectures were identified: a rapid scenario featuring a 33-day outbound transfer, a 30-day surface stay, and a 90-day return (total ≈ 153 days), and a feasible scenario combining a 56-day outbound transfer, a 35-day surface stay, and a 135-day return (total ≈ 226 days). Both trajectories were validated through full ephemeris computation, confirming heliocentric coherence within the CA21-anchored orbital plane and physically realistic departure and arrival velocities. The 2031 alignment minimizes plane-change penalties and yields energetically balanced outbound and inbound arcs. These findings demonstrate that short-duration, reversible Earth–Mars missions can be designed from early asteroid-derived orbital templates, establishing a predictive framework for identifying future high-velocity transfer opportunities.

Abstract: Early orbital predictions for the near-Earth asteroid 2001 CA21 — based on 2015 JPL Horizons data — revealed a trajectory with an eccentricity of 0.777, a perihelion of 0.373 AU, and an aphelion extending to 2.967 AU. While subsequent refinements altered the asteroid’s actual orbit, these initial parameters provided a valuable reference template for designing rapid Earth–Mars transfers. By anchoring transfer-plane geometry to the CA21 orbital solution, we identified novel mission opportunities capable of drastically reducing interplanetary travel times.Our analysis highlights the 2031 opposition as the most favorable case: a 56-day transfer with , only marginally exceeding the New Horizons record, and , challenging but potentially addressable with aerocapture or braking tug concepts. A 33-day extreme trajectory is also geometrically possible in 2031, though requiring departure energies ( ) and arrival speeds ( ) well beyond current or near-term propulsion systems.Earlier opportunities in 2027 and 2029, while closer in time, impose even higher energetic barriers (departure velocities ~19 km/s, arrival ~17.5–20 km/s), underscoring the counterintuitive reality that shorter Earth–Mars distances do not guarantee lower transfer energy.This study therefore proposes a new methodological framework: using early asteroid orbital predictions as trajectory templates to identify both feasible and aspirational rapid-transit missions. By linking NEO orbital geometry with Lambert-based transfer analysis, we establish practical benchmarks for propulsion and capture technologies, demonstrating that 2031 provides a near-term achievable baseline, while also defining the aspirational frontier of one-month Mars missions.

Abstract: As the near-Earth space domain becomes increasingly congested, the field of space domain awareness (SDA) has risen in importance and motivated the use of non-traditional sensors. One such class of sensor is high frequency (HF) radar operating in line-of-sight (LOS) mode, as their large surveillance field-of-view enables simultaneous tracking of several objects. HF signals are, however, subject to ray bending and group retardation when propagating through the ionosphere. This paper demonstrates the development and implementation of a method for calculating the ionospheric correction for HF LOS satellite observations, using three-dimensional numerical ray tracing through a climatological model ionosphere. Defence Science and Technology Group's experimental HF LOS radar was deployed during a SpaceFest trial in late 2020, and recorded observations of resident space objects (RSOs). The ionospheric correction is applied to these observations and compared to propagations obtained from the reported two line elements (TLEs) of the RSOs to assess the correction performance. The results demonstrate that, even during weak ionospheric conditions, ray tracing through a climatological model ionosphere produces a significant improvement in the residuals between the range measurements and TLEs.

Abstract: In this study, we report the exceptional observations of amplified eastward subauroral polarization streams (SAPS) made in the topside ionosphere near magnetic midnight during 2015-2016 in 17 events. Our results show the eastward SAPS flows streaming sunward after magnetic midnight and antisunward before magnetic midnight: in concert with the duskward-intruding dawn convection cell. These demonstrate that the eastward SAPS flow’s amplification was primarily caused by (1) the extension of equatorward-directed convection electric field (EC) to subauroral latitudes. Further evidence is provided by one set of correlated magnetosphere-ionosphere (M-I) conjugate observations showing (2) the inward (earthward) EC field near the inner-magnetosphere plasmapause (on the tailward side) and the emerging eastward SAPS in the topside ionosphere and thus implying (3) the EC field’s mapping-down and propagation to subauroral latitudes in the coupled M-I system. In the topside ionosphere, the amplified eastward SAPS flow reached ~3000 m/s in magnitude within the deep plasma density trough, where the electron temperature maximized at ~7000 K. There, (4) the underlying positive feedback mechanisms created favorable ionospheric conditions for SAPS growth. Finally, we conclude that the combination of these (1-4) mechanisms played a crucial role in the amplification of the near-midnight eastward SAPS flows observed.

Abstract: The present work discusses the birth of the Universe via quantum tunneling through a potential barrier, based on quantum cosmology, taking into account a running cosmological constant. We consider the Friedmann-Lemaître-Robertson-Walker (FLRW) metric with positively curved spatial sections ($k = 1$) and the matter content is a dust perfect fluid. The model was quantized by the Dirac formalism, leading to a Wheeler-DeWitt equation. We solve that equation both numerically and using a WKB approximation. We studied the behavior of tunneling probabilities $TP_{WKB}$ and $TP_{int}$ by varying the energy $E$ of the dust perfect fluid, the phenomenological parameter $\nu$, the present value of the Hubble function $H_0$ and the constant energy density $\rho^0_\Lambda$, all the last three parameters associated with the time-varying cosmological constant.

Abstract: This paper conducts a technical study on a method for determining the occurrence threshold of wind shear based on historical sounding data. After analyzing the impact of low-altitude wind shear on aircraft flight safety, a method for determining the occurrence threshold of wind shear based on historical sounding data is proposed. A statistical analysis of the sounding data from the test area over a period of 15 years from 2010 to 2024has been conducted, which includes the occurrence events and probability statistics of 1000m wind shear for all 12 months of the year. Simulation results validate the feasibility and effectiveness of the method for determining the occurrence threshold of wind shear based on historical sounding data in the test area, forming a method that can be extended to all altitude ranges of aircraft flight and all flight regions globally. This statistical method provides a technical foundation for the efficient detection of wind shear at local airports and enhances flight safety at these airports.

Abstract: Three stations in the Asia-Pacific region are selected to form two time comparison links. By comparing the correction accuracy of the satellite orbits and clock deviations of the PPP-B2b messages broadcast by the two GEO satellites of BDS-3 C59 and C61, and taking the time comparison results obtained by the GBM post-ephemeris as a reference, the accuracy of the time comparison of the PPP-B2b messages broadcast by the two GEO satellites C59 and C61 was evaluated. The results show that the accuracy of time comparison between C59 and C61 is similar, but the stability and availability of C59 are better than those of C61. In addition, five IGS/IGMAS stations were selected to evaluate the accuracy of the PPP-B2b message transmitted by the C59 and C61 GEO satellites for BDS-3 positioning, using the IGS/IGMAS weekly solution positioning results as a reference. The results show that the static positioning of PPP-B2b broadcasted by C59 and C61 can reach centimeter level, and the simulated kinematic positioning can reach decimeter level. The positioning accuracy of C59 is higher than that of C61.