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10 pages, 1545 KiB

Open AccessArticle

Additional Solar System Gravitational Anomalies

by Les Coleman

Symmetry 2021, 13(9), 1696; https://doi.org/10.3390/sym13091696 - 14 Sep 2021

Viewed by 2943

This article is motivated by uncertainty in experimental determinations of the gravitational constant, G, and numerous anomalies of up to 0.5 percent in Newtonian gravitational force on bodies within the solar system. The analysis sheds new light through six natural experiments within the solar system, which draw on published reports and astrophysical databases, and involve laboratory determinations of G, orbital dynamics of the planets and the moons of Earth and Mars, and non-gravitational acceleration (NGA) of ‘Oumuamua and comets. In each case, values are known for all variables in Newton’s Law

F = \frac{G \cdot M \cdot m}{R^{2}}

, except for the gravitational constant, G. Analyses determine the gravitational constant’s observed value,

\hat{G}

, which—across the six settings—varies with the mass of the smaller, moving body, m, so that

\hat{G} = G \times (0.998 + 0.00016 \times \ln (m))

. While further work is required, this examination shows a scale-related Newtonian gravity effect at scales from benchtop to Solar System, which contributes to the understanding of symmetry in gravity and has possible implications for Newton’s Laws, dark matter, and formation of structure in the universe. Full article

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9 pages, 248 KiB

Open AccessArticle

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

by Les Coleman

Symmetry 2021, 13(3), 510; https://doi.org/10.3390/sym13030510 - 20 Mar 2021

Cited by 1 | Viewed by 3860

Abstract

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. Full article

(This article belongs to the Special Issue 30 Years of Econophysics: Symmetry in Physics and Economics)

17 pages, 381 KiB

Open AccessArticle

Anomalous Sun Flyby of 1I/2017 U1 (`Oumuamua)

by Klaus Wilhelm and Bhola N. Dwivedi

Galaxies 2020, 8(4), 83; https://doi.org/10.3390/galaxies8040083 - 7 Dec 2020

Cited by 2 | Viewed by 4224

Abstract

The findings of Micheli et al. (Nature2018, 559, 223–226) that 1I/2017 U1 (`Oumuamua) showed anomalous orbital accelerations have motivated us to apply an impact model of gravity in search for an explanation. A small deviation from the [...] Read more.

1 / r

potential, where r is the heliocentric distance, is expected for the gravitational interaction of extended bodies as a consequence of this model. This modification of the potential results from an offset of the effective gravitational centre from the geometric centre of a spherically symmetric body. Applied to anomalous Earth flybys, the model accounts for energy gains relative to an exact Kepler orbit and an increased speed of several spacecraft. In addition, the flat rotation profiles of eight disk galaxies could be explained, as well as the anomalous perihelion advances of the inner planets and the asteroid Icarus. The solution in the case of `Oumuamua is also based on the proposal that the offset leads to an approach and flyby trajectory different from a Kepler orbit without postulating cometary activity. As a consequence, an adjustment of the potential and centrifugal orbital energies can be envisaged outside the narrow uncertainty ranges of the published post-perihelion data without a need to re-analyse the original data. The observed anomalous acceleration has been modelled with respect to the orbit solutions JPL 16 and “Pseudo-MPEC” for 1I/`Oumuamua. Full article

(This article belongs to the Collection A Trip across the Universe: Our Present Knowledge and Future Perspectives)

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5 pages, 1790 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Early Observations of the Interstellar Comet 2I/Borisov

by Chien-Hsiu Lee

Geosciences 2019, 9(12), 519; https://doi.org/10.3390/geosciences9120519 - 17 Dec 2019

Cited by 1 | Viewed by 3339

Abstract

2I/Borisov is the second ever interstellar object (ISO). It is very different from the first ISO ’Oumuamua by showing cometary activities, and hence provides a unique opportunity to study comets that are formed around other stars. Here we present early imaging and spectroscopic follow-ups to study its properties, which reveal an (up to) 5.9 km comet with an extended coma and a short tail. Our spectroscopic data do not reveal any emission lines between 4000–9000 Angstrom; nevertheless, we are able to put an upper limit on the flux of the C2 emission line, suggesting modest cometary activities at early epochs. These properties are similar to comets in the solar system, and suggest that 2I/Borisov—while from another star—is not too different from its solar siblings. Full article

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