Structure of spherically symmetric objects: a study based on structure scalars

The aim of this paper is to explore the consequences of extra curvature terms mediated from f(R, T, Q) (where Q ≡ R μ ν T μ ν ) theory on the formation of scalar functions and their importance in the study of populations who are crowded with regular relativistic objects. For this purpose, we model our system comprising of non-rotating spherical geometry formed due to gravitation of locally anisotropic and radiating sources. After considering a particular f(R, T, Q) model, we form a peculiar relation among Misner-Sharp mass, tidal forces, and matter variables. Through structure scalars, we have modeled shear, Weyl, and expansion evolutions equations. The investigation for the causes of the irregular distribution of energy density is also performed with and without constant curvature conditions. It is deduced that our computed one of the f(R, T, Q) structure scalars (Y T ) has a vital role to play in understanding celestial mechanisms in which gravitational interactions cause singularities to emerge.

Tides and Volcanoes: A Historical Perspective

In this paper, we examine the origins and the history of the hypothesis for an influence of tidal forces on volcanic activity. We believe that exploring this subject through a historical perspective may help geoscientists gain new insights in a field of research so closely connected with the contemporary scientific debate and often erroneously considered as a totally separated niche topic. The idea of an influence of the Moon and Sun on magmatic processes dates back to the Hellenistic world. However, it was only since the late 19th century, with the establishment of volcano observatories at Mt. Etna and Vesuvius allowing a systematic collection of observations with modern methods, that the “tidal controversy” opened one of the longest and most important debates in Earth Science. At the beginning of the 20th century, the controversy assumed a much more general significance, as the debate around the tidal influence on volcanism developed around the formulation of the first modern theories on the origins of volcanism, the structure of the Earth’s interior and the mechanisms for continental drift. During the same period, the first experimental evidence for the existence of the Earth tides by Hecker (Beobachtungen an Horizontalpendeln über die Deformation des Erdkörpers unter dem Einfluss von Sonne und MondVeröffentlichung des Königl, 1907, 32), and the Chamberlin–Moulton planetesimal hypothesis (proposed in 1905 by geologist Thomas Chrowder Chamberlin and astronomer Forest Ray Moulton) about the “tidal” origin of the Solar System, influenced and stimulated new researches on volcano-tides interactions, such as the first description of the “lava tide” at the Kilauea volcano by Thomas Augustus Jaggar in 1924. Surprisingly, this phase of gradual acceptance of the tidal hypothesis was followed by a period of lapse between 1930 to late 1960. A new era of stimulating and interesting speculations opened at the beginning of the seventies of the 20th century thanks to the discovery of the moonquakes revealed by the Apollo Lunar Surface Experiment Package. A few years later, in 1979, the intense volcanism on the Jupiter’s moon Io, discovered by the Voyager 1 mission, was explained by the tidal heating produced by the Io’s orbital eccentricity. In the last part of the paper, we discuss the major advances over the last decades and the new frontiers of this research topic, which traditionally bears on interdisciplinary contributions (e.g., from geosciences, physics, astronomy). We conclude that the present-day debate around the environmental crisis, characterized by a large collection of interconnected variables, stimulated a new field of research around the complex mechanisms of mutual interactions among orbital factors, Milankovitch Cycles, climate changes and volcanism.

The Apparent Tail of the Galactic Center Object G2/DSO

Observations of the near-infrared excess object G2/DSO increased attention toward the Galactic center and its vicinity. The predicted flaring event in 2014 and the outcome of the intense monitoring of the supermassive black hole in the center of our Galaxy did not fulfill all predictions about a significantly enhanced accretion event. Subsequent observations addressed the question concerning the nature of the object because of its compact shape, especially during its periapse in 2014. Theoretical approaches have attempted to answer the contradictory behavior of the object, resisting the expected dissolution of a gaseous cloud due to tidal forces in combination with evaporation and hydrodynamical instabilities. However, assuming that the object is instead a dust-enshrouded young stellar object seems to be in line with the predictions of several groups and observations presented in numerous publications. Here we present a detailed overview and analysis of the observations of the object that have been performed with SINFONI (VLT) and we provide a comprehensive approach to clarify the nature of G2/DSO. We show that the tail emission consists of two isolated and compact sources with different orbital elements for each source rather than an extended and stretched component as it appeared in previous representations of the same data. Considering our recent publications, we propose that the monitored dust-enshrouded objects are remnants of a dissolved young stellar cluster whose formation was initiated in the circumnuclear disk. This indicates a shared history, which agrees with our analysis of the D- and X-sources.

Droplet evaporation method applied to test the efficacy of Zincum metallicum 30c on stressed and non-stressed wheat seeds

Background: The droplet evaporation method (DEM) has been recently proposed as a possible tool to test the efficacy of ultra high dilutions (UHDs) [1]. Here we applied the same methodology consisting in the evaporation of droplets from leakages obtained by placing wheat seeds in UHDs to test whether DEM patterns vary in function of the tested treatment: Zincum metallicum 30c (ZM), lactose 30c as dynamized control (L), and unsuccussed, undiluted water as negative control (C). Since our previous study [1] showed that there is a significant increase in the UHD action in the stressed model, with respect to the non-stressed one, also in the present experiment we tested ZM, L and C on both stressed (s-seeds) and non-stressed wheat seeds (ns-seeds). Aims: The aim of the experiment was to test whether treatments ZM, L, and C applied on ns- and s-seeds influence the DEM pattern characteristics. Materials and methods: Whole, undamaged wheat seeds (Triticum aestivum cv. Inallettabile, harvesting year 2010) were used for the experiment, following the experimental protocol described in [1]. The distinction between s- and ns-seeds is based upon different storing conditions from the harvest until the analysis day: the ns-seeds were kept in controlled conditions at 5°C and in the dark, whereas the s-seeds were kept in lab at varying temperature, humidity and light conditions. As far as treatment preparation is concerned, ZM and L were obtained from triturations 3c (received from the Federal University of Rio de Janeiro) by vertical mechanical succussions and following dilutions; negative control (C) was ultra-pure water from the same water batch used for dilutions. The experiment was repeated on 6 days within one month; each seed lot (ns- and s-seeds) was analyzed on 3 different days (s-seeds on 10th, 11th and 24th February 2014 and ns-seeds on 12th, 26th February and 3th March 2014), with three treatment-replicates for ZM and L and two for C, three repetitions for each treatment-replicate and 5 droplets per repetition (360 patterns for each seed lot). The complexity degree of polycrystalline structures obtained from the evaporating droplets was measured by means of the ImageJ software [2] by calculating their local connected fractal dimensions (LCFD). The data on moon phase, moon position and moon distance from Earth at the beginning of each evaporation process were collected from the online tool virtuelles Telescope [3]. All data were processed by a three-way ANOVA at a significance level of p ≤ 0.05. Correlations between the moon data and LCFD were evaluated by r Pearson coefficient. Results: The effect of the treatment on LCFD values of DEM patterns was significant only in the stressed model: ZM showed a crystallization inhibiting action vs. C on all 3 analysis days, whereas a significant difference between ZM and L could be observed only on first and third analysis day (Fig 1a). ANOVA analysis showed that the overall LCFD means for the s-seed lot differed significantly between each other: 1.33 (a) for C, 1.26 (b) for L, and 1.19 (c) for ZM. Moreover, the LCFD values of both seed lots showed a strong day factor influence. A possible explanation of this finding might be the influence of the moon (position, phase, and distance from Earth) on the crystallization process: strong correlation between the LCFD of the patterns and moon data were found (r values were from -0.72 to -0.97). Figure 1: Graphical representation of the mean local connected fractal dimension values (LCFD) of droplet evaporation patterns obtained from stressed and non-stressed wheat seeds following treatments with Zincum metallicum 30c (ZM), lactose 30c (L), and unsuccussed/undiluted water (C). Discussion: The present study confirms a pre-sensitization effect towards UHD action in stressed models: a significant inhibiting effect of ZM 30c was found in all experimentation day. Furthermore, the strong correlations observed between the LCFD values and moon data indicate that the complexity of polycrystalline structures from evaporating droplets of wheat seed leakages might be affected by tidal forces. Since DEM needs to be standardized, these correlations can be considered only simultaneous and not causal, however their strength gives good reasons for further studies. Conclusions: The results of the present pilot-study seem to encourage further DEM experiments on s-seeds following UHD treatments. For further confirmation of the inhibiting effect of ZM on s-seeds, germination tests should be planned. Finally, the performance of DEM experimentations during days and hours with equal tidal influence on gravity might be helpful for the reduction of the day factor. Keywords:Ultra high dilutions, droplet evaporation method, patterns, Zincum metallicum

Cherenkov Gravitational Radiation during the Radiation Era

Cherenkov radiation may occur whenever the source is moving faster than the waves it generates. In a radiation dominated universe, with equation-of-state w=1/3, we have recently shown that the Bardeen scalar-metric perturbations contribute to the linearized Weyl tensor in such a manner that its wavefront propagates at acoustic speed w=1/3. In this work, we explicitly compute the shape of the Bardeen Cherenkov cone and wedge generated respectively by a supersonic point mass (approximating a primordial black hole) and a straight Nambu-Goto wire (approximating a cosmic string) moving perpendicular to its length. When the black hole or cosmic string is moving at ultra-relativistic speeds, we also calculate explicitly the sudden surge of scalar-metric induced tidal forces on a pair of test particles due to the passing Cherenkov shock wave. These forces can stretch or compress, depending on the orientation of the masses relative to the shock front’s normal.

Modeling of solar magnetic field using the kinematic-gravitational ion dynamo model

In present article the kinematic-gravitational ion dynamo model accounting for influence of tidal forces on electric currents in ionized substances is applied to modeling of the magnetic field of the Sun. Estimates of currents and field values obtained using a seven-layer model indicate that tidal forces influence is not insignificant. A correlation method for assessment of the Sun’s polarity was created and applied for a detailed analysis of the polarity of magnetic field of the Sun in the 21 and 22 cycles.

Analytical Calculations of Some Effects of Tidal Forces on Plants on the International Space Station

Among the phenomena attributable to the Moon’s actions on living organisms, one of them seems to be related to analytical fluid mechanics: along the route of the International Space Station around the Earth, experiments on plants have revealed leaf oscillations. A parametric resonance due to a short period of microgravitational forces could explain these oscillations. Indeed, Rayleigh-Taylor’s instabilities occurring at the interfaces between liquid-water and its vapor verify a second-order Mathieu differential equation. This is the case of interfaces existing in the xylem channels of plant stems filled with sap and air-vapor. The magnitude of the instabilities depends on the distances between the Moon, the Sun, and the Earth. They are analogous, but less spectacular, to those that occur during ocean tides.

Atmospheric Anomaly Analysis Related to Ms > 6.0 Earthquakes in China during 2020–2021

The attention towards links of atmospheric parameter variation and earthquakes has increased exponentially by utilizing new methods and more accurate observations. Persistent research makes it possible to gain insight into the precursor mechanism of earthquakes. In this paper, we studied the universality of detecting atmospheric anomalies associated with earthquakes based on tidal force fluctuation in China for earthquakes of Ms > 6.0, and explored the influence of tidal force on tectonic stress. The data of air temperature, geopotential height, ozone mixing ratio, and relative humidity from the National Center for Environmental Prediction (NCEP) were analyzed to reveal the spatiotemporal variation of atmospheric anomalies at multiple isobaric surfaces. Furthermore, the coupling of atmospheric parameters was investigated. The results showed that continuous solicitation exerted by tidal forces could change the strength of tectonic stress that causes earthquakes. The evolution pattern of air temperature, geopotential height, and relative humidity could be supported by atmospheric thermal vertical diffusion, while the anomalies of ozone mixing ratio was not evident. This verified the feasibility of detecting multi-parameter atmospheric anomalies associated with earthquakes based on tidal force fluctuation. Our results provide more evidence for understanding the atmospheric precursor characteristics of earthquakes.

Hydrodynamic influences on sedimentology and geomorphology of nearshore parts of carbonate ramps: Holocene, NE Yucatán Shelf, Mexico

ABSTRACT Although carbonate ramps are ubiquitous in the geologic record, the impacts of oceanographic processes on their facies patterns are less well constrained than with other carbonate geomorphic forms such as isolated carbonate platforms. To better understand the role of physical and chemical oceanographic forces on geomorphic and sedimentologic variability of ramps, this study examines in-situ field measurements, remote-sensing data, and hydrodynamic modeling of the nearshore inner ramp of the modern northeastern Yucatán Shelf, Mexico. The results reveal how sediment production and accumulation are influenced by the complex interactions of the physical, chemical, and biological processes on the ramp. Upwelled, cool, nutrient-rich waters are transported westward across the ramp and concentrated along the shoreline by cold fronts (Nortes), westerly regional currents, and longshore currents. This influx supports a mix of both heterozoan and photozoan fauna and flora in the nearshore realm. Geomorphically, the nearshore parts of this ramp system in the study area include lagoon, barrier island, and shoreface environments, influenced by the mixed-energy (wave and tidal) setting. Persistent trade winds, episodic tropical depressions, and winter storms generate waves that propagate onto the shoreface. Extensive shore-parallel sand bodies (beach ridges and subaqueous dune fields) of the high-energy, wave-dominated upper shoreface and foreshore are composed of fine to coarse skeletal sand, lack mud, and include highly abraded, broken and bored grains. The large shallow lagoon is mixed-energy: wave-dominated near the inlet, it transitions to tide-dominated in the more protected central and eastern regions. Lagoon sediment consists of Halimeda-rich muddy gravel and sand. Hydrodynamic forces are especially strong where bathymetry focuses water flow, as occurs along a promontory and at the lagoon inlet, and can form subaqueous dunes. Explicit comparison among numerical models of conceptual shorefaces in which variables are altered and isolated systematically demonstrates the influences of the winds, waves, tides, and currents on hydrodynamics across a broad spectrum of settings (e.g., increased tidal range, differing wind and wave conditions). Results quantify how sediment transport patterns are determined by wave height and direction relative to the shoreface, but tidal forces locally control geomorphic and sedimentologic character. Similarly, the physical oceanographic processes acting throughout the year (e.g., daily tides, episodic winter Nortes, and persistent easterly winds and waves) have more impact on geomorphology and sedimentology of comparable nearshore systems than intense, but infrequent, hurricanes. Overall, this study provides perspectives on how upwelling, nutrient levels, and hydrodynamics influence the varied sedimentologic and geomorphic character of the nearshore areas of this high-energy carbonate ramp system. These results also provide for more accurate and realistic conceptual models of the depositional variability for a spectrum of modern and ancient ramp systems.