scholarly journals The ‘Oumuamua Encounter: How Modern Cosmology Handled Its First Black Swan

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 510
Author(s):  
Les Coleman
Keyword(s):  
Solar System ◽  
Comparative Study ◽  
Popular Literature ◽  
Research Strategy ◽  
Black Swan ◽  
Planetary Formation ◽  
Macroscopic Object ◽  
Specific Instance ◽  
Modern Cosmology ◽  
Current Paradigm

The first macroscopic object observed to have come from outside the solar system slipped back out of sight in early 2018. 1I/2017 U1 ‘Oumuamua offered a unique opportunity to test understanding of gravity, planetary formation and galactic structure against a true outlier, and astronomical teams from around the globe rushed to study it. Observations lasted several months and generated a tsunami of scientific (and popular) literature. The brief window available to study ‘Oumuamua created crisis-like conditions, and this paper makes a comparative study of techniques used by cosmologists against those used by financial economists in qualitatively similar situations where data conflict with the current paradigm. Analyses of ‘Oumuamua were marked by adherence to existing paradigms and techniques and by confidence in results from self and others. Some, though, over-reached by turning uncertain findings into graphic, detailed depictions of ‘Oumuamua and making unsubstantiated suggestions, including that it was an alien investigator. Using a specific instance to test cosmology’s research strategy against approaches used by economics researchers in comparable circumstances is an example of reverse econophysics that highlights the benefits of an extra-disciplinary lens.

Boron Behavior During the Evolution of the Early Solar System: The First 180 Million Years

Elements ◽  
2017 ◽  
Vol 13 (4) ◽  
pp. 231-236 ◽  
Author(s):  
Charles K. Shearer ◽  
Steven B. Simon
Keyword(s):  
Solar System ◽  
Solar Nebula ◽  
Nuclear Reactions ◽  
Terrestrial Planets ◽  
The Sun ◽  
Planetary Formation ◽  
Light Elements ◽  
Early Solar System ◽  
Spallation Reactions ◽  
Magma Oceans

The behavior of boron during the early evolution of the Solar System provides the foundation for how boron reservoirs become established in terrestrial planets. The abundance of boron in the Sun is depleted relative to adjacent light elements, a result of thermal nuclear reactions that destroy boron atoms. Extant boron was primarily generated by spallation reactions. In the initial materials condensing from the solar nebula, boron was predominantly incorporated into plagioclase. Boron abundances in the terrestrial planets exhibit variability, as illustrated by B/Be. During planetary formation and differentiation, boron is redistributed by fluids at low temperature and during crystallization of magma oceans at high temperature.

A Comparative Study on Interpretation of Planet from Al-Quran and Astronomy Views

2017 ◽  
Vol 15 (2) ◽  
pp. 213-239
Author(s):  
Khairussaadah Wahid ◽  
Mohd Saiful Anwar Mohd Nawawi ◽  
Saadan Man
Keyword(s):  
Solar System ◽  
Comparative Study ◽  
Physical Nature ◽  
Physical Characteristics ◽  
The Difference ◽  
Modern Astronomy

Abstract The interpretation submitted by the translator of mashaf Quran against the pronouncement of al-kawkab and al-kawakib means ‘star’. Based on the studies from the modern astronomy, both words refer to a planet. The study of the meaning of al-kawkab and al-kawakib is about explaining more appropriate meanings based on the context of Islamic astronomy. The main objective of this study is to identify the meaning of al-kawkab and al-kawakib terms in al-Quran and to analyze the correlation between Quranic commentaries with modern discoveries of planets in the solar system. Methods of comparison between the views of Quranic commentaries and modern astronomy are highlighted with reference based on classical and contemporary tafseers, and modern astronomy literature. The study found that there are four passages that discuss physical characteristics of planets. In addition, the reason that may be adduced to explain appropriate translations for the words al-kawkab and al-kawakib as ‘planet’ is based on the majority of Quranic commentaries and research on the difference in physical nature of planets and stars. In conclusion, the is no difference between Quranic commentaries and modern astronomy related to planets and their features. Thus the pronouncement of al-kawkab and al-kawakib in the Quran refers to a planet, not a star.

scholarly journals Comparative Study on Planetary Magnetosphere in the Solar System

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1673
Author(s):  
Ching-Ming Lai ◽  
Jean-Fu Kiang
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar System ◽  
Comparative Study ◽  
Magnetic Reconnection ◽  
Tilt Angle ◽  
Planetary Magnetosphere ◽  
Field Distributions ◽  
Mhd Simulations ◽  
The Magnetic Field

The magnetospheric responses to solar wind of Mercury, Earth, Jupiter and Uranus are compared via magnetohydrodynamic (MHD) simulations. The tilt angle of each planetary field and the polarity of solar wind are also considered. Magnetic reconnection is illustrated and explicated with the interaction between the magnetic field distributions of the solar wind and the magnetosphere.

The Formation and Evolution of the Solar System

2018 ◽  
Author(s):  
Mikhail Marov
Keyword(s):  
Solar System ◽  
Observational Data ◽  
Extrasolar Planets ◽  
Inner Core ◽  
Experimental Studies ◽  
Radial Distance ◽  
Planetary Formation ◽  
Sequence Of Events ◽  
Formation And Evolution ◽  
Dust Disks

The formation and evolution of our solar system (and planetary systems around other stars) are among the most challenging and intriguing fields of modern science. As the product of a long history of cosmic matter evolution, this important branch of astrophysics is referred to as stellar-planetary cosmogony. Interdisciplinary by way of its content, it is based on fundamental theoretical concepts and available observational data on the processes of star formation. Modern observational data on stellar evolution, disc formation, and the discovery of extrasolar planets, as well as mechanical and cosmochemical properties of the solar system, place important constraints on the different scenarios developed, each supporting the basic cosmogony concept (as rooted in the Kant-Laplace hypothesis). Basically, the sequence of events includes fragmentation of an original interstellar molecular cloud, emergence of a primordial nebula, and accretion of a protoplanetary gas-dust disk around a parent star, followed by disk instability and break-up into primary solid bodies (planetesimals) and their collisional interactions, eventually forming a planet. Recent decades have seen major advances in the field, due to in-depth theoretical and experimental studies. Such advances have clarified a new scenario, which largely supports simultaneous stellar-planetary formation. Here, the collapse of a protosolar nebula’s inner core gives rise to fusion ignition and star birth with an accretion disc left behind: its continuing evolution resulting ultimately in protoplanets and planetary formation. Astronomical observations have allowed us to resolve in great detail the turbulent structure of gas-dust disks and their dynamics in regard to solar system origin. Indeed radio isotope dating of chondrite meteorite samples has charted the age and the chronology of key processes in the formation of the solar system. Significant progress also has been made in the theoretical study and computer modeling of protoplanetary accretion disk thermal regimes; evaporation/condensation of primordial particles depending on their radial distance, mechanisms of clustering, collisions, and dynamics. However, these breakthroughs are yet insufficient to resolve many problems intrinsically related to planetary cosmogony. Significant new questions also have been posed, which require answers. Of great importance are questions on how contemporary natural conditions appeared on solar system planets: specifically, why the three neighbor inner planets—Earth, Venus, and Mars—reveal different evolutionary paths.

scholarly journals Chemical diversity of super-Earths as a consequence of formation

2020 ◽  
Vol 493 (4) ◽  
pp. 4910-4924 ◽  
Author(s):  
Jennifer Scora ◽  
Diana Valencia ◽  
Alessandro Morbidelli ◽  
Seth Jacobson
Keyword(s):  
Solar System ◽  
Planet Formation ◽  
Initial Conditions ◽  
Chemical Diversity ◽  
Planetary Formation ◽  
Iron Depletion ◽  
Giant Impacts

ABSTRACT Recent observations of rocky super-Earths have revealed an apparent wider distribution of Fe/Mg ratios, or core to mantle ratios, than the planets in our Solar system. This study aims to understand how much of the chemical diversity in the super-Earth population can arise from giant impacts during planetary formation. Planet formation simulations have only recently begun to treat collisions more realistically in an attempt to replicate the planets in our Solar system. We investigate planet formation more generally by simulating the formation of rocky super-Earths with varying initial conditions using a version of symba, a gravitational N-body code, that incorporates realistic collisions. We track the maximum plausible change in composition after each impact. The final planets span a range of Fe/Mg ratios similar to the Solar system planets, but do not completely match the distribution in super-Earth data. We only form a few planets with minor iron-depletion, suggesting other mechanisms are at work. The most iron-rich planets have a lower Fe/Mg ratio than Mercury, and are less enriched than planets such as Kepler-100b. This indicates that further work on our understanding of planet formation and further improvement of precision of mass and radius measurements are required to explain planets at the extremes of this Fe/Mg distribution.

A Comparative Study on Neural Network Based Controllers Used in Grid-Interactive Solar System

2018 ◽  
Vol 19 (6) ◽  
Author(s):  
Moushumi Patowary ◽  
Gayadhar Panda ◽  
Bimal C. Deka
Keyword(s):  
Neural Network ◽  
Solar System ◽  
Comparative Study ◽  
Power Quality ◽  
Comparative Assessment ◽  
Control Technique ◽  
Stability And Convergence ◽  
Current Harmonics ◽  
Current Controller ◽  
Non Linear

Abstract This paper proposes a comparative assessment of NN based current controllers followed by hardware validation towards power quality improvement in grid-interactive VSI controlled solar system. The steady state errors, transient disturbances and high current harmonic effects encountered in conventional linear PI and PR controllers are nullified by employing intelligent adaptive current controller. Three adaptive current control strategies viz. ADALINE-LMS, ALLMS, and VLAS-LMS are identified by using artificial neural network topology having been controlled by different weight-regulating algorithms which helps in minimizing current harmonics generated by the widespread use of VSI, non-linear loads, faults and uncertain polluted grid. A comprehensive comparative study is driven from the proposed adaptive controller's stability and convergence criterion, current magnitudes calculated at different power zones, % overshoot, settling time and power quality and analyzed under numerous operating conditions. From the comparative assessment performed in between conventional and intelligent current controllers, it is confirmed that the intelligent control technique performs best under the non-linear loads and transient conditions whereas all the controllers perform equally good under the linear loads. Proposed methods are simulated in MATLAB/Simulink and their effectiveness is compared in terms of time responses, stability and low-order current harmonics compensation capability. The robustness of the intelligent current controller is established through the experimental performances using dSPACE RTI 1202.

scholarly journals Ice giant system exploration within ESA’s Voyage 2050

2021 ◽  
Author(s):  
Leigh N. Fletcher ◽  
Ravit Helled ◽  
Elias Roussos ◽  
Geraint Jones ◽  
Sébastien Charnoz ◽  
...  
Keyword(s):  
Solar System ◽  
European Space Agency ◽  
White Paper ◽  
Planetary Formation ◽  
Ring Systems ◽  
International Partnership ◽  
Space Agency ◽  
Science Planning

AbstractOf all the myriad environments in our Solar System, the least explored are the distant Ice Giants Uranus and Neptune, and their diverse satellite and ring systems. These ‘intermediate-sized’ worlds are the last remaining class of Solar System planet to be characterised by a dedicated robotic mission, and may shape the paradigm for the most common outcome of planetary formation throughout our galaxy. In response to the 2019 European Space Agency call for scientific themes in the 2030s and 2040s (known as Voyage 2050), we advocated that an international partnership mission to explore an Ice Giant should be a cornerstone of ESA’s science planning in the coming decade, targeting launch opportunities in the early 2030s. This article summarises the inter-disciplinary science opportunities presented in that White Paper [1], and briefly describes developments since 2019.

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