scholarly journals Observed and Theoretical Values of the Nutations

1971 ◽  
Vol 9 ◽  
pp. 186-189
Author(s):  
R.O. Vicente
Keyword(s):  
Great Majority ◽  
Point Of View ◽  
The Sun ◽  
Astronomical Observations ◽  
The Earth ◽  
External Forces

We are here concerned with the nutations that appear in the motion of the Earth because of the existence of the external forces due to the Sun and Moon, that is, the forced nutations.We can consider the nutations divided in two groups from the point of view of their values and the precision attained by astronomical observations. The first group comprises the nutations that have values greater than 1″ and in this group we have the nutation of period 18.6 yr called the principal nutation and the value of this nutation in obliquity is called the constant of nutation. The second group comprises the nutations with values smaller than 1″ and corresponds to the great majority of all other nutations.

James Bradley, Sailing on the Thames

Lightspeed ◽  
2019 ◽  
pp. 49-57
Author(s):  
John C. H. Spence
Keyword(s):  
Eighteenth Century ◽  
Experimental Evidence ◽  
The Sun ◽  
Theory Of Relativity ◽  
Speed Of Light ◽  
Astronomical Observations ◽  
The Earth ◽  
Independent Estimate ◽  
The Universe ◽  
At Home

The story of the astronomical observations of James Bradley in the eighteenth century, whose measurements of the small movements of a star throughout the year provided an independent estimate of the speed of the Earth around the Sun relative to the speed of light. His work provided the first experimental evidence in support of Copernicus’s theory that the earth is in motion, and against the idea that it is stationary at the center of the universe. His simple telescope at home, his brilliant idea and perseverance, and his life’s work and influence. The importance of his result for the development of Einstein’s theory of relativity and for theories of the Aether in the following centuries.

scholarly journals Connection of large earthquakes occurring moment with the movement of the Sun and the Moon and with the Earth crust tectonic stress character

2010 ◽  
Vol 10 (7) ◽  
pp. 1629-1633 ◽  
Author(s):  
M. K. Kachakhidze ◽  
R. Kiladze ◽  
N. Kachakhidze ◽  
V. Kukhianidze ◽  
G. Ramishvili
Keyword(s):  
Tectonic Stress ◽  
Point Of View ◽  
The Sun ◽  
Compression Stress ◽  
The Moon ◽  
Caucasus Region ◽  
The Earth ◽  
Triggering Factor ◽  
Exogenous Factors ◽  
Large Earthquakes

Abstract. It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region.

scholarly journals Astromimetics

2018 ◽  
Vol 5 ◽  
pp. 184954351879434 ◽  
Author(s):  
Vuk Uskoković ◽  
Victoria M Wu
Keyword(s):  
Materials Science ◽  
Fine Particles ◽  
Great Majority ◽  
Point Of View ◽  
Iron Core ◽  
Colloidal Form ◽  
The Earth ◽  
Celestial Bodies ◽  
Intended Use

Composite, multifunctional fine particles are likely to be at the frontier of materials science in the foreseeable future. Here we present a submicron composite particle that mimics the stratified structure of the Earth by having a zero-valent iron core, a silicate/silicide mantle, and a thin carbonaceous crust resembling the biosphere and its biotic deposits. Particles were formulated in a stable colloidal form and made to interact with various types of healthy and cancer cells in vitro. A selective anticancer activity was observed, promising from the point of view of the intended use of the particles for tumor targeting across the blood–brain barrier. As an extension of the idea underlying the fabrication of a particle mimicking the planet Earth, we propose a new field of mimetics within materials science: astromimetics. The astromimetic approach in the context of materials science consists of the design of particles after the structure of celestial bodies. With Earth being the most chemically diverse and fertile out of all the astral bodies known, it is anticipated that the great majority of astromimetic material models will fall in the domain of geo-inspired ones.

scholarly journals Rotation of the Rigid Earth

1997 ◽  
Vol 165 ◽  
pp. 295-300
Author(s):  
P. Bretagnon
Keyword(s):  
Time Domain ◽  
Time Span ◽  
Euler Angles ◽  
The Sun ◽  
The Moon ◽  
The Earth ◽  
Rigid Earth ◽  
The Time Domain ◽  
Tesseral Harmonics ◽  
External Forces

AbstractWe present the results of a solution of the Earth’s rotation built with analytical solutions of the planets and of the Moon’s motion. We take into account the influence of the Moon, the Sun and all the planets on the potential of the Earth for the zonal harmonics Cj,0 for j from 2 to 5, and also for the tesseral harmonics C2,2, S2,2C3,k, S3,k for k from 1 to 3 and C4,1, S4,1. We determine three Euler angles ψ, ω, and φ by calculating the components of the torque of the external forces with respect to the geocenter in the case of the rigid Earth. The analytical solution of the precession-nutation has been compared to a numerical integration over the time span 1900–2050. The differences do not exceed 16 μas for ψ and 8 μas for ω whereas the contribution of the tesseral harmonics reaches 150 μas in the time domain.

The Earth but a Satellite of the Sun

1958 ◽  
Vol 11 (2) ◽  
pp. 150-156 ◽  
Author(s):  
E. G. R. Taylor
Keyword(s):  
General Public ◽  
Point Of View ◽  
The Sun ◽  
Similar Role ◽  
The Earth ◽  
New Ideas ◽  
Detective Stories ◽  
Fred Hoyle ◽  
The Universe

New ideas of a really fundamental character are always received with horror and alarm by the general public, and are vigorously repudiated. When Fred Hoyle, in a brilliant series of broadcasts, remarked that his physico-mathematical calculations indicated that newly created hydrogen was being continuously injected into the Universe, the B.B.C. had to take hasty countermeasures. A well-known authoress of detective stories and religious pl ys, followed by a respected professor of science, declared on the air that the earlier t lks had been merely speculative. A similar role was filled in 1543 by the theologian Andreas Osiander, who added a Preface to Copernicus's startling book De Revolutionibus Orbium Coelestium (the author having just died), to the effect that he had only intended as a mathematical hypothesis, not as a matter of fact, to picture a rotating globe revolving round the Sun. From the point of view of pure geometry it was, it is true, merely a matter of a change of coordinates. People settled back comfortably for another sixty or seventy years, until Galileo made certain awkward observations with his new telescope.

scholarly journals III. Part of a letter from Leonard Euler, Prof. Math. At Berlin, and F. R. S. To the Rev. Mr. Caspar Wetstein, Chaplain to his Royal Highness the Prince of Wales, concerning the gradual approach of the Earth to the Sun. Translated from the French, by S. T. M. D. F. R. S

1750 ◽  
Vol 46 (493) ◽  
pp. 203-205
Keyword(s):  
The Sun ◽  
Astronomical Observations ◽  
The Earth ◽  
History Of ◽  
Gradual Approach

Monsieur le Monnier writes to me, that there is, at Leyden , an Arabic Manuscript of lbn jounis (if I am not mistaken in the Name, for it is not distinctly wrote in the Letter), which contains a History of Astronomical Observations.

scholarly journals On the distribution of radium in the Earth's crust and on the Earth’s internal heat

1906 ◽  
Vol 77 (519) ◽  
pp. 472-485 ◽  
Keyword(s):  
Temperature Gradient ◽  
Internal Heat ◽  
Point Of View ◽  
Earth’S Crust ◽  
The Sun ◽  
The Earth ◽  
Earth's Crust

Professor Rutherford has given a calculation which suggests that there may be enough radium in the earth to account for the temperature gradient observed near the surface. The question is of great interest from a cosmical point of view. For if we find that the earth’s internal heat is due to radio-activity, and if we assume, as has been usual, that this heat is due to some vestiges of the cause operative in the sun and stars, it would follow that these latter are heated by radio-active changes also.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

Spots on the Sun and Life on the Earth

2019 ◽  
Vol 15 (1) ◽  
pp. 73-77
Author(s):  
Valentina V. Ukraintseva ◽  
Keyword(s):  
The Sun ◽  
The Earth
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