Search Results (1,637)

Time governs human experience, yet human beings continually seek to govern time. Within Jewish mysticism, time functions as a foundational and elusive dimension of human experience, serving as a dynamic arena for theosophical speculation, theurgical action, and spiritual transformation. In this context, the influential nineteenth-century Hasidic work Bnei Yissachar by Rabbi Tzvi Elimelech Shapira of Dinov (1783–1841) occupies a unique position, offering a systematic and nuanced theology of sacred time. While previous scholarship has recognized the importance of sacred time in his thought, this study uncovers a complex reciprocal temporal mechanism that balances two dialectical poles: cosmic subordination and human mastery. Through a close reading of Shapira’s homilies, this article demonstrates how he navigates the tension between fixed, pre-ordained divine temporal matrices, typified by the linguistic and numerical hidden structure of the Sabbath, and active human agency capable of reshaping the qualitative influx of time, illustrated by the sanctification of the New Moon and the Passover Seder night. By integrating Lurianic kabbalistic frameworks, gematria, and linguistic ontology with embodied ritual practices, Shapira reframes the Jewish calendar as an interactive, experience-oriented relationship between the human and the divine. Full article

The current interest in lunar exploration led by the Artemis program is pushing scientists to search for lunar water deposits directly on the surface of the Moon, using small robotic rovers. The Institute of Experimental and Applied Physics, Czech Technical University, Prague (IEAP CTU), is developing a miniature Timepix3-based detector called Neutron HardPix, which is capable of mapping water deposits using non-invasive detection of neutrons created underground by cosmic rays and thermalized by hydrogen. This neutron spectrometer measures count rate variations in thermal, epithermal and fast neutrons attributed to hydrogen abundance in the lunar subsurface, while monitoring cosmic radiation as a natural source of neutrons. Neutron HardPix is based on the miniature (<0.1 U, 130 g) radiation monitor HardPix, and has significant space heritage. Full article

Jigan (寂感), derived from the Book of Changes, which states “when remaining in serene stillness without stirring, it attains universal penetration once stirred by resonance (jiran budong ganer suitong 寂然不動感而遂通).” It describes the profound subtlety of the Zhouyi. On the other hand, Jizhao (寂照) is a Sinicized Buddhist interpretation denoting the non-dual integration of true suchness and prajñā wisdom. Jigan developed into an ontological framework during the Song Dynasty (960–1279), while jizhao took shape during the Wei-Jin period. Philosophically, both manifest a non-dual substance-function structure “quiescence as resonance” and “quiescence as illumination.” They jointly serve as the foundational model for mind-nature cultivation and spiritual transcendence. From this theory of cultivation, however, divergent spiritual aspirations of Confucianism and Buddhism. Confucianism elucidates the principle of universal oneness of all things through quietude-resonance, pursuing the spiritual realm of sagehood. By contrast, Buddhism penetrates through self-attachment and dharma-attachment via quiescent illumination, thereby detaching from all karmic conditions, and manifests Prajñā. Confucianism integrates the practice of jigan into its ritual education, sacrificial ceremonies and daily disciplinary norms, rendering it a practical pathway for sustaining the cosmic-ethical order and generating ritual authority. Buddhism implements jizhao in meditation, precepts, and monastic life, constructing an enlightenment-oriented sacred community. Jigan and jizhao represent two distinct paths of religious transformation and spiritual attainment. This paper compares how both emanate from the ontological state of “serene stillness without stirring” into practical cultivation manifested as “resonance penetrating all things” or “simultaneity of illumination and function”, and ultimately shape divergent modes of sacredness and forms of social integration. While jigan and jizhao reveal a structural convergence in the cultivation theories of Confucianism and Buddhism, they also demonstrate disparate orientations in their spiritual aspirations. Full article

Merging galaxy clusters represent one of the most powerful macroscopic laboratories in the Universe for searching for new physics within the dark sector. High-velocity cosmic collisions inherently separate the dark matter and stellar components from the highly collisional, X-ray-emitting intracluster gas. These massive systems provide an ideal environment to probe the fundamental nature of dark matter, specifically testing whether it behaves as a strictly collisionless particle or exhibits non-zero self-interactions. While pioneering systems like the Bullet Cluster historically demonstrated the macroscopic decoupling of dark and ordinary matter, the field has evolved into a sophisticated discipline driven by multi-disciplinary methodologies. This review synthesizes recent theoretical and empirical advances in interpreting post-collision dynamics. It examines how the synergy of combined approaches—integrating multi-wavelength observations from gravitational lensing and X-ray mapping with high-fidelity N-body hydrodynamical simulations—allows the translation of macroscopic spatial observables into stringent constraints on microscopic particle properties. Through this synthesis, the work evaluates how leveraging heterogeneous merger ensembles can reliably advance the ongoing search for physics beyond the standard cosmological model. Full article

Measurements of charge-changing cross-sections were developed as a method for determining proton radii, particularly for unstable, short-lived nuclei. Such cross-sections must be measured with high precision to determine the precise charge radii. However, there are complexities in the experimental method leading to uncertainties in determining precise nuclear radii. Therefore, good models describing the complex physics of charged particle interactions are needed in order to validate the experimental method and to estimate the contribution of systematic uncertainties. GEANT4 is a Monte Carlo simulation code widely used to describe interactions in heavy-ion collisions over a broad energy range, ranging from atomic physics to cosmic-ray energies. Experimental measurements of charge-changing reactions for carbon isotopes ^10,12C on different secondary targets were performed. In the present work, the experimental detector geometry, beam profile, and detector configuration were implemented in GEANT4 simulations in order to reproduce the experimental conditions as closely as possible. The experimentally obtained spectra are compared with the corresponding GEANT4 simulations to validate the interpretation of the measured spectra and assess systematic effects. Also, the secondary particle yield ratio is deduced and compared with GEANT4 results. Full article

A new mechanism for the formation of spectral–spatial distortions in cosmic microwave background radiation near primordial massive compact objects (such as primordial black holes) at redshifts from $z\sim 1000$ to ∼100 is proposed. After hydrogen recombination, the radiation from these objects leads to a significant increase in the population of hydrogen subordinate levels in their surrounding environment. Consequently, this allows for the observation of a Fraunhofer-like absorption spectrum in the cosmic microwave background. Such a distortion is formed due to the temperature difference between matter and relic radiation at the corresponding epoch. Ultimately, we should observe circular absorption or emission features around the objects with small angular sizes. These subordinate hydrogen lines currently lie in the radio wavelength range. Estimates indicate that the effect under consideration is accessible for the observations with planned large radiotelescopes. The possibility of the proposed mechanism lies in the ability of an object (e.g., accretion disk around black hole) to emit few-eV photons that populate the $n=2,3,4$ and higher levels of hydrogen, enabling the required excitation. Full article

Primordial black holes (PBHs) in the asteroid-mass range, with typical masses ${10}^{17}\mathrm{g}\lesssim M\lesssim {10}^{23}\mathrm{g}$, have drawn significant recent attention as viable dark matter candidates. The peak frequencies of photons emitted via Hawking radiation from asteroid-mass PBHs range from infrared to $\gamma$-ray bands. We calculate expected local transit rates for extended PBH mass distributions that could comprise all dark matter. We evaluate prospects for detecting Hawking-radiated photons from local PBH transits through the inner Solar System and from PBH explosions in the far outer edges of the Solar System. We consider several existing and proposed ground-based and space-based instruments sensitive to photons from the radio band to ultrahigh-energy $\gamma$-rays. We find that the proposed instruments, such as the All-sky Medium Energy Gamma-ray Observatory eXplorer (AMEGO-X) satellite, can reliably detect PBH transits within $\mathcal{O}\left(0.1\mathrm{AU}\right)$ of the Earth, while the High Altitude Water Cherenkov (HAWC) observatory and Large High Altitude Air Shower Observatory (LHAASO) are both sensitive to PBH explosions out to $\mathcal{O}\left(0.1\mathrm{pc}\right)$ and $\mathcal{O}\left(0.5\mathrm{pc}\right)$, respectively. We conclude by specifically considering potential companion electromagnetic signatures in the case of a PBH explosion about ${10}^3\mathrm{AU}$ from Earth, which has been suggested as a potential source for the ∼220 PeV ultrahigh-energy KM3-230213A neutrino event observed by the KM3NeT collaboration in 2023. Whereas we find that the recent KM3NeT event would not have yielded detectable electromagnetic signals—due to its location on the sky, proposed distance from Earth, and the offline status of the HAWC observatory at that time—we demonstrate that future PBH explosions at comparable distances could yield electromagnetic signals measurable from Earth, depending on the alignment of the PBH burst with detector fields of view. Full article

Radio occultation offers high vertical resolution, global coverage, and low sensitivity to clouds and precipitation, making it a useful complement to existing atmospheric sounding techniques. The YunYao constellation, the first commercial meteorological remote sensing constellation of China, supplies a large number of GNSS-RO temperature profile products, yet the quality of its wet atmospheric profiles remains undocumented. Using operational radiosonde data from 43 stations over southern China (97–123°E, 17–31°N) during boreal winter and early spring (1 November 2025 to 31 March 2026) as reference, this study evaluates the accuracy, error characteristics, and applicability of the YunYao wet atmospheric temperature profile product, with COSMIC-2 as an independent benchmark. YunYao yields 4.77 times the matched sample volume of COSMIC-2 over the same domain and period, while its RMSE is only 0.20–0.42 °C higher. Within 50–925 hPa, the YunYao profiles agree closely with radiosondes, with RMSE generally within 1–2 °C, a weak, spatially uniform cold bias, and small diurnal differences. Below 925 hPa, near-surface error grows markedly, dominated by enhanced random error rather than systematic error, with inland cold and coastal warm bias. A January maximum of random error is possibly related to super-refraction during peak winter monsoon cold surges, and a March sign reversal of the bias possibly related to the seasonal increase in boundary layer moisture ahead of the pre-flood season. With weak cold bias correction, YunYao temperature profiles are highly usable within 50–925 hPa, while data below 925 hPa require strict quality control. Full article

Through deep intertextual analysis of Tianzhu Jiangsheng Chuxiang Jingjie (Explanations on the Incarnation of God, hereafter, Jingjie), a late Ming Dynasty work by Jesuit missionary Giulio Aleni, this paper explores three levels at which the text creatively interprets Confucian and Daoist thought in the inculturation of Catholic spirituality in China, also drawing implications of Aleni’s historical inculturation for the contemporary inculturation of Christianity in China today. At the Christological level, Jingjie’s opening hymn champions the “Cosmic Christ” as a universal sage-king who creates all things with benevolence, thereby establishing an ontological foundation for its spiritual theory. At the spiritual level, Jingjie’s discourse on “proclaiming benevolence for the universal edification” characterizes the “Cosmic Christ” as a sage-king or “person of ren” (仁人), thereby acculturating the moral focus of Christian “imitatio Christi” within the Chinese tradition of spiritual cultivation. And at the level of praxis, Jingjie employs the “Dao-Vessel” distinction from the Yijing (易经, Book of Changes) and the “spiritual wandering” concept from the Zhuangzi to interpret the practice of “contemplating images” (观像) as a path of “proceeding from the traces below-form to explore the spirit above-form,” transcending the pictorial medium to attain a state of “wandering with creation.” Jingjie is therefore not only a richly illustrated narrative work but also a deeply practical spiritual guide that systematically interprets Ignatius of Loyola’s Exercitia Spiritualia through the lens of Chinese heart–mind cultivation, offering a valuable historical case study for the profound integration of Catholic theology and Chinese culture in contemporary China. Full article

The effect of a tendency toward coplanarity of sub-cores in gamma-ray–hadron families, observed in high-mountainous and stratospheric experiments with X-ray emulsion chambers at super-high energies, is discussed. Based on simulations within the framework of the traditional FANSY 2.0/QGSJ model and the radical FANSY 2.0/2D model, the possibility of studying coplanar energy flows in the cores of Extensive Air Showers (EAS) arriving at the surface of the ADRON-55 calorimeter is considered. An assessment of the sensitivity of the ADRON-55 calorimeter for studying the coplanarity effect of energy flows in EAS cores has been made. Full article

Although the standard model of cosmology ($\mathrm{\Lambda }$CDM) has been successful in explaining a wide range of observational phenomena, it still faces significant limitations, particularly regarding the nature and properties of the dark sector of the universe. These challenges motivate the exploration of alternative approaches that can deepen our understanding of cosmic evolution. This study proposes an extension of the $\mathrm{\Lambda }$CDM model by incorporating irreversible processes through a viscous fluid with out of equilibrium pressure. This fluid interacts dynamically with the dark sector components, offering new possibilities for describing the expansion of the universe. To constrain the proposed scenarios, we perform a Bayesian statistical analysis using the Pantheon+ Type Ia supernova compilation, Cosmic Chronometers, and DESI DR2 Baryon Acoustic Oscillation measurements. The observational results show that all three interaction models successfully reproduce the late-time expansion history while preserving a dark matter barotropic index close to the pressureless limit expected in the standard cosmological scenario. In contrast, the dark energy barotropic index consistently favors positive values, suggesting a mild departure from the cosmological constant description. The incorporation of Cosmic Chronometers and, particularly, BAO measurements substantially improves the constraints on the matter sector, leading to a significant reduction in the uncertainty of the present dark matter density parameter, whereas the bulk-viscosity parameter and the asymptotic ratio remain only weakly constrained. Finally, a Bayesian model comparison based on the Bayes factor shows that the interacting dissipative models remain observationally compatible with the reference $\mathrm{\Lambda }$CDM cosmology. According to the Jeffreys scale, the resulting Bayesian evidence is inconclusive, indicating that current observations neither favor nor disfavor these extensions with respect to the standard cosmological model. Full article

As China’s first commercial low Earth orbit meteorological constellation, Tianmu-1 (TM) radio occultation (RO) provides high-density observations, with approximately 30,000 profiles per day globally, offering new opportunities for research in observationally sparse regions. TM RO bending angle and refractivity retrievals from June to December 2023 are evaluated using ERA5 reanalysis, global radiosonde observations, and COSMIC-2 RO as reference datasets. TM observation errors are further estimated using the three-cornered hat (3CH) method. The results show that, in the upper troposphere and lower stratosphere, TM bending angle biases are within ±0.19%, ±0.40%, and ±0.37% relative to ERA5 (8–30 km), radiosonde (8–25 km), and COSMIC-2 (8–30 km), respectively. The corresponding refractivity biases are within ±0.09%, ±0.21%, and ±0.14%, respectively. Both bending angle and refractivity from TM RO exhibit high accuracy and precision. The observation errors estimated using the 3CH method show a clear latitudinal dependence. The observation errors in the tropics (±30° latitude) are larger than those in the middle and high latitudes. This study quantitatively characterizes the accuracy, precision, and error structure of TM RO bending angle and refractivity, providing a quantitative basis for future quality control and observation error specification in numerical weather prediction data assimilation. Full article

The Hubble tension is usually formulated as a disagreement between two determinations of a single scalar parameter, $H_0$, within an exactly isotropic FLRW model. We develop a quantitative framework in which the tension is instead treated as a consistency test of the scalar FLRW compression of cosmological data in a homogeneous but anisotropically expanding Bianchi type I background. Beyond synthesizing established results on Bianchi I kinematics, null geodesics and optical propagation, the original contribution is a worked weak-shear, axisymmetric calculation that maps a specified shear history into a low-redshift luminosity-distance quadrupole. The calculation explicitly separates the direction-dependent redshift–affine-parameter mapping from the Jacobi-focusing contribution and then propagates the resulting distance quadrupole through an analytic polar-cap toy window. For freely decaying shear we obtain $A_D\left(z\right)=-B_{H0}+(2q_0-1)B_{H0}z/2+(5-q_0-18q_0^2+6j_0)B_{H0}{z}^2/12+\mathcal{O}(z^3,B_{H0}^2)$, where $B_{H0}=(H_{\Vert 0}-H_{\perp 0})/H_0$ and $j_0$ is the mean jerk parameter. A representative BBN limit, ${\mathrm{\Omega }}_{\sigma 0}\lesssim {10}^{-23}$, implies $|B_{H0}|\lesssim 9.5\times {10}^{-12}$ and a distance-modulus quadrupole below approximately $2.4\times {10}^{-11}$ mag at $z=0.15$. The early-Universe bound used in this comparison is adopted from previous work and is not itself a new result of the present analysis; the novelty is its propagation through the derived direction-dependent redshift and Sachs–Jacobi mapping into quantitative limits on the luminosity-distance quadrupole and on the catalog-window bias of an isotropic $H_0$ fit. By contrast, even a maximally aligned one-percent directional shift requires ${\mathrm{\Omega }}_{\sigma 0}\simeq 2.5\times {10}^{-5}$, while a shift comparable with the Planck 2018–SH0ES 2022 benchmark separation requires ${\mathrm{\Omega }}_{\sigma 0}\simeq 1.8\times {10}^{-3}$. Thus the minimal shear-only model cannot resolve the tension, although the framework supplies a falsifiable program for testing sustained late-time anisotropy with supernovae, BAO, distance-ladder measurements and future standard sirens. Full article

This work proposes a compact phenomenological parametrization in which the quantity observationally identified with the cosmological constant is interpreted as the present effective value, ${\Lambda }_{eff}(t_0)$, of a dark component that remains close to the Lambda cold dark matter ($\Lambda$CDM) model over the recent cosmological epoch but is not required to remain constant in the remote future. The purpose is not to introduce dynamical dark energy in general, which has already been extensively investigated, but to formulate a minimal subclass in which the present effective value associated with $\Lambda$ and the asymptotic fate of the expansion are explicitly separated. Within this framework, the current dominance of the dark component does not require an increase in ${\Lambda }_{eff}$: it can arise because the matter density dilutes as $a^{-3}$, whereas ${\Lambda }_{eff}$ varies more slowly. A delayed-decay function is introduced, normalized to the present effective value and allowing ${\Lambda }_{eff}\to 0$ as $a\to \infty$. In the strong version of the parametrization, identified by $n_f>2$, the effective component is asymptotically unable, by itself, to sustain cosmic acceleration indefinitely. The proposal is not presented as a microscopic theory of dark energy, but as a background-level effective dark-sector parametrization that may serve as a phenomenological benchmark for particle-cosmology scenarios and can be constrained through measurements of $H(z)$ and cosmological distances, together with observational constraints on $w(a)$. Full article