Abstract: Space weather events triggered by solar activity impact critical technologies like the Global Navigation Satellite System (GNSS) by causing atmospheric imbalances that alter ionospheric electron density. This study investigates the geospace response to the severe geomagnetic storms of October 2024, focusing on the coupling and compositional exchange between the ionosphere and thermosphere. Data were analyzed from two near-magnetic conjugate mid-latitude African stations, Rabat (RABT) and Hermanus (HNUS), using GNSS-TEC measurements alongside thermospheric circulation observations from NASA GOLD and solar wind indices from OMNIWeb. The October 2024 storm, which reached a minimum Dst of -333 nT, drove a negative ionospheric storm phase marked by Total Electron Content (TEC) depletions exceeding 50 TECU. This response was driven by storm-time thermospheric upwelling of N2-rich air, which lowered the O/N2 ratio and accelerated plasma loss via charge-exchange reactions. Furthermore, a distinct hemispheric asymmetry was observed, as the equatorward thermospheric circulation in the Northern Hemisphere arrived before that of the Southern Hemisphere. Direct post-processing of ECEF coordinates using RTKLIB revealed a "GNSS Paradox": while positioning accuracy significantly degraded at HNUS with errors increasing by up to 270%, it counterintuitively improved at RABT, where errors reached their minimum during the main and early recovery phases of the storm. These findings highlight that the technological impact of severe space weather is determined not just by storm magnitude, but by the specific sign and spatial structure of the regional ionospheric response.

Abstract: We prove that the null cone is enough: at every event in Minkowski spacetime, the null cone carries a two-dimensional conformal field theory with spectrum \Delta_{\ell} = \ell +1 , unifying all massless fields of spin \ell = 0,\frac{1}{2},1,\frac{3}{2},2 through pure geometry. The framework is classical throughout. From two postulates—four-dimensional Minkowski spacetime and the Isometric Sampling Condition (the requirement that field sampling on a lattice be a unitary isomorphism)—the unique Lorentz-invariant propagator is G(x,y) = \sin (\Omega \sqrt{-\sigma^2 - i\epsilon}) / (\Omega \sqrt{-\sigma^2 - i\epsilon}) , where the Feynman i\epsilon prescription selects the unique L^2 branch in the spacelike region. The RKHS normalisation K(x,x) = 1 forces G = 1 on the null cone, so the full two-point function is controlled entirely by a 2D CFT on the transverse S^2 , yielding \Delta_{\ell} = \ell +1 . Fermionic statistics arise from the \mathbb{Z}_2 holonomy of an \mathrm{SL}(2,\mathbb{C}) fibre bundle without any additional postulate. Seven independent paths—spanning operator algebra, tractor calculus, antenna theory, and celestial holography—converge on this result. At large angular scales (\ell \lesssim 30) , the condition G = 1 forces the CMB angular power spectrum C_{\ell} toward a geometric constant, consistent with the Planck anomaly.

Abstract: We present an innovative, cost-effective framework integrating laboratory Hyperspectral Imaging (HSI) of the BECHAR 010 lunar meteorite with ground-based lunar HSI and supervised Machine Learning (ML) to generate high-fidelity mineralogical maps. A \SI{3}{\milli\metre} thin section of BECHAR 010 was imaged under a microscope with a \SI{30}{\milli\metre} focal length lens at \SI{150}{\milli\metre} working distance, using 6x binning to increase the signal-to-noise ratio, producing a data cube (X $\times$ Y $\times$ $\lambda$ = $791 \times 1024 \times 224$, \SI{0.24}{\milli\metre} $\times$ \SI{0.2}{\milli\metre} resolution) across \SIrange{400}{1000}{\nano\metre} (224 bands, \SI{2.7}{\nano\metre} spectral sampling, \SI{5.5}{\nano\metre} FWHM spectral resolution) using a Specim FX10 camera. Ground-based lunar HSI was captured with a Celestron 8SE telescope (\SI{3}{\kilo\metre}/pixel), yielded a data cube ($371 \times 1024 \times 224$). Solar calibration was performed using a Spectralon reference (\SI{99}{\percent} reflectance \SI{< 2}{\percent} error) ensured accurate reflectance spectra. A Support Vector Machine (SVM) with a radial basis function kernel, trained on expert-labeled spectra, achieved \SI{93.7}{\percent} classification accuracy (5-fold cross-validation) for olivine (\SI{92}{\percent} precision, \SI{90}{\percent} recall) and pyroxene (\SI{88}{\percent} precision, \SI{86}{\percent} recall) in BECHAR 010. Local Interpretable Model-agnostic Explanations (LIME) identified key wavelengths (e.g., \SI{485}{\nano\metre}, \SI{22.4}{\percent} for M3; \SI{715}{\nano\metre}, \SI{20.6}{\percent} for M6) across 10 pre selected regions (M1 to M10), indicating olivine-rich (Highland-like) and pyroxene-rich (Mare-like) compositions. Spectral Angle Mapper (SAM) analysis revealed angles from \SI{0.26}{\radian} to \SI{0.66}{\radian}, linking M3 and M9 to Highlands and M6 and M10 to Mares. K-means clustering of lunar data identified 10 mineralogical clusters (\SI{88}{\percent} accuracy), validated against Chandrayaan-1 Moon mineralogy Mapper ($\rm M^3$) data (\SI{140}{\metre}/pixel, \SI{10}{\nano\metre} spectral resolution). A novel push-broom HSI approach with telescope, achieves 0.8 arcsec resolution for lunar spectroscopy, inspiring full-sky multi-object spectral mapping.

Abstract: This paper explores the fundamental nature of spacetime from the perspective of emergent causal structures, rooted in quantum mechanical principles. We propose a theoretical framework that treats spacetime not as a pre-existing background, but as a collective phenomenon arising from the interaction of quantum causal relations. By analyzing the constraints of causality and quantum coherence, we derive key implications for the emergence of classical spacetime geometry and the limits of local realism. Our results suggest a new way to bridge quantum mechanics and gravitational theory, providing a foundation for future studies in quantum gravity and spacetime physics.

Abstract:

Rapid subauroral flows occurring at unusually high magnetic latitudes during quiet times and weak substorms are rarely investigated and poorly understood. We investigated the phenomenon in a comprehensive way by using multi-instrument and multipoint satellite observations along with a set of computed variables. We specified 5 Subauroral Polarization Streams (SAPS) and 28 Subauroral Ion Drifts (SAID) events observed in the Northern Hemisphere by spacecraft F18 in 2013. Driven by the strong poleward SAPS-SAID electric (E) fields (90–190 mV/m), high-latitude SAPS-SAID flows reached supersonic velocities (2400-5200 m/s) and developed at unusually high (≥68^o) magnetic latitudes, in the dusk sector, sometimes on the dayside. The high-latitude SAPS/SAID flows appeared in the deep main trough and mostly within the downward region-2 current suggesting their previous development. Their underlying vertical upward/downward drifts, driven by eastward/westward zonal E fields, imply positive feedback mechanisms in progress. Earthward energy depositions into the high-latitude SAPS and SAID channels indicate magnetospheric electromagnetic energy generations in their respective voltage generators. Conjugate observations demonstrate the development of large outward SAID E field (E_X≈10 mV/m) on 28 October 2013 and SAPS E field (E_X≈10 mV/m) on 14 October 2013 at L≈10 R_E on a short timescale at dusk.

Abstract: The exceptionally strong geomagnetic storm of 10-11 May 2024 injected new energetic protons and electrons in the terrestrial radiation belts, creating extraordinary conditions to study the loss mechanisms scattering these particles into the atmosphere after the storm. For the first time, four electron belts were observed during several weeks. We show that this structure was due to electron loss highly depending on specific positions. Using the proton and electron fluxes measured by the Energetic Particle Telescope EPT on board PROBA-V, we determine the lifetimes of these populations depending on their energy ranges and positions. We show that the lifetimes are much longer for protons than for electrons, which allows us to determine their time variations independently. For electrons, the wave-particle loss mechanisms depend on the background ionosphere-plasmasphere density. The lifetimes determined after the May 2024 and 10 October 2024 big events are compared with average ones to understand their unusual specificity for the formation of four and three belts, respectively. For the injected protons of 9.5 to 13 MeV, the lifetime is minimum at L~1.9 where the fluxes are maximum, showing a lifetime depending on the flux intensity. Loss is due to pitch angle diffusion and collisions with electrons and nuclei in the ambient plasma and neutral atmosphere. At the outer edge of the proton belt, the flux is depleted at all energies after the geomagnetic perturbation, and we determine that the progressive time of refilling after the storm reaches generally more than 40 days. There is an excellent discrimination between the different populations of energetic electrons (0.5-8 MeV) and the injected protons (9.5-13 MeV) that are still observed several months after the event. Such results contribute to advancing understanding of the interactions between the terrestrial atmosphere and space radiation.

Abstract: This paper presents a conducting channel model aimed at elucidating the generation of high-energy particles within a plasma chamber. Initially, the chamber is charged with neutral hydrogen gas at a density of approximately ~3.3×10²²/m³, equivalent to 1 torr at 300K under ideal gas conditions. A Townsend discharge (dark discharge), driven by an externally imposed electric potential (500-1000V) across the cathode and anode, is utilized to induce partial ionization of the hydrogen gas. Once a stable conducting channel with a high conductivity is established, a low electric potential (e.g., 100V-500V) is introduced to sustain the current in the conducting channel. Our investigation then delves into the impact of a high electron emissivity cathode, such as lanthanum hexaboride (LaB6) during an arc discharge. We develop a theoretical model of the conducting channel that may emerge under these conditions. As the cathode surface undergoes heating, emitted thermionic electrons form a localized layer of negative charge density, leading to an electric potential dip. Our multi-fluid simulations unveil the emergence of electron-ion two-stream instability owing to the high-density electron layer, leading to the appearance of multiple potential peaks and dips, each measuring several to tens of kV. We delineate a set of conditions conducive to the formation of these potential peaks and dips within the conducting channel. Our proposed scenario furnishes a framework for elucidating electron and ion acceleration within a weakly ionized plasma chamber.

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:

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.