scholarly journals DECOHERENCE AND GRAVITATIONAL BACKGROUDS

2002 ◽  
Vol 17 (06n07) ◽  
pp. 1003-1012 ◽  
Author(s):  
SERGE REYNAUD ◽  
BRAHIM LAMINE ◽  
ASTRID LAMBRECHT ◽  
PAUOLO MAIA NETO ◽  
MARC-THIERRY JAEKEL
Keyword(s):  
Gravitational Waves ◽  
Effective Temperature ◽  
Planetary Motion ◽  
The Moon ◽  
The Earth ◽  
Gravitational Scattering ◽  
Decoherence Process ◽  
Very High ◽  
Negligible Influence

We study the decoherence process associated with the scattering of stochastic gravitational waves. We discuss the case of macroscopic systems, such as the planetary motion of the Moon around the Earth, for which gravitational scattering is found to dominate decoherence though it has a negligible influence on damping. This contrast is due to the very high effective temperature of the background of gravitational waves in our galactic environment.

Review Lecture: The dynamical properties and internal structures of the Earth, the Moon and the planets

1972 ◽  
Vol 328 (1574) ◽  
pp. 301-336 ◽  
Keyword(s):  
Internal Structure ◽  
Recent Progress ◽  
High Pressures ◽  
Artificial Satellites ◽  
The Moon ◽  
The Earth ◽  
Internal Structures ◽  
Theoretical Investigations ◽  
Dynamical Properties ◽  
Very High

The aim of this review is to bring together and relate recent progress in three subjects - the internal structure of the Earth, the behaviour of materials at very high pressures and the dynamical properties of the planets. Knowledge of the internal structure of the Earth has been advanced in recent years, particularly by observations of free oscillations of the whole Earth excited by the very largest earthquakes; as a consequence, it is clear that K. E. Bullen’s hypothesis that bulk modulus is a smooth function of pressure irrespective of composition is close to the truth for the Earth. Understanding of the behaviour of materials at very high pressure has increased as a result both of experiments on the propagation of shock waves and of theoretical investigations along a number of lines and it can now be seen that Bullen’s hypothesis is not true irrespective of chemical composition and crystal structure but that it happens to apply to the Earth because of particular circumstances. Studies of the orbits of artificial satellites and space probes have led to better knowledge of the dynamics of the Moon, Mars and Venus, and there have also been recent improvements in the traditional studies of Uranus and Neptune. Our knowledge of the dynamics of the planets is on the whole rather restricted, and Bullen’s hypothesis only applies directly to the Moon (for which the application is trivial) and possibly to Mars; the dynamical properties do none the less set fairly restrictive limits to the models that can be constructed for other planets. It would be possible for all planets to have cores of similar composition to the Earth ’s, surrounded by mantles of different sorts, silicates for the terrestrial planets and mostly hydrogen for Jupiter, Saturn, Uranus and Neptune.

CELESTIAL OPTICAL INTERFEROMETRY: A NEW TOOL FOR ULTRAHIGH PRECISION STUDIES IN GRAVITY

2008 ◽  
Vol 17 (03n04) ◽  
pp. 617-626 ◽  
Author(s):  
C. S. UNNIKRISHNAN ◽  
G. T. GILLIES
Keyword(s):  
Gravitational Waves ◽  
Equivalence Principle ◽  
Gravitational Constant ◽  
Low Frequency ◽  
Artificial Satellites ◽  
Length Scale ◽  
The Moon ◽  
The Earth ◽  
Tremendous Progress ◽  
Laser Sources

The tremendous progress in the science and technology of timing devices and laser sources has reached a stage where their stability and coherence are sufficient for implementing unbalanced interferometers over a length scale exceeding the Earth–Moon distance. This opens up the possibility of optical homodyne interferometry over such distances, either to the Moon or to artificial satellites that are at large distances from the Earth. The precision of the measurement of changes in the orbital distance would increase by a factor of 104 or more, enabling new ultrahigh precision tests of the equivalence principle, study of gravitomagnetism, and of subtle gravitational phenomena, including the constancy of the gravitational constant and possible gravitational expansion of space. It would enable geodesy and tide studies with unprecedented precision. Such interferometers would also be useful for the detection and study of low frequency gravitational waves.

Newton's Early Thoughts on Planetary Motion: A Fresh Look

1964 ◽  
Vol 2 (2) ◽  
pp. 117-137 ◽  
Author(s):  
Derek T. Whiteside
Keyword(s):  
Planetary Motion ◽  
Planetary Theory ◽  
The Moon ◽  
Conventional View ◽  
The Earth

The conventional view of the prehistory of Newton's synthesis in the Principia of his predecessors' work in planetary theory and terrestrial gravitation is still not seriously changed from that which Newton himself chose to impose on his contemporaries at the end of his life. In his own words:‘… the same year ‘1666’ I began to think of gravity extending to ye orb of the Moon & having found out how to estimate the force wth wch [a] globe revolving within a sphere presses the surface of the sphere from Keplers rule of the periodical times of the Planets being in a sesquialterate proportion of their distances from the centers of their Orbs, & having deduced that the forces wch keep the Planets in their orbs must [be] reciprocally as the squares of their distances from the centers about wch they revolve: & thereby compared the force requisite to keep the Moon in her Orb with the force of gravity at the surface of the earth, & found them answer pretty nearly …’

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

Probable Structure and Nature of the Formations on the Reverse Side of the Moon According to Photometric Measurements of Lunar Photographs

1962 ◽  
Vol 14 ◽  
pp. 39-44
Author(s):  
A. V. Markov
Keyword(s):  
The Moon ◽  
Probable Structure ◽  
The Earth ◽  
Interplanetary Station ◽  
Photometric Measurements ◽  
Automatic Interplanetary Station

Notwithstanding the fact that a number of defects and distortions, introduced in transmission of the images of the latter to the Earth, mar the negatives of the reverse side of the Moon, indirectly obtained on 7 October 1959 by the automatic interplanetary station (AIS), it was possible to use the photometric measurements of the secondary (terrestrial) positives of the reverse side of the Moon in the experiment of the first comparison of the characteristics of the surfaces of the visible and invisible hemispheres of the Moon.

scholarly journals Interpreting Locked Photographic Data: The Case of Apollo 17 Photo GPN-2000-00113

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Pyrrhon Amathes ◽  
Paul Christodoulides
Keyword(s):  
Experimental Data ◽  
Computer Simulations ◽  
The Moon ◽  
Geometrical Analysis ◽  
Apparent Position ◽  
Apollo Program ◽  
The Earth ◽  
Novel Approach ◽  
The World ◽  
The Moment

Photography can be used for pleasure and art but can also be used in many disciplines of science, because it captures the details of the moment and can serve as a proving tool due to the information it preserves. During the period of the Apollo program (1969 to 1972), the National Aeronautics and Space Administration (NASA) successfully landed humans on the Moon and showed hundreds of photos to the world presenting the travel and landings. This paper uses computer simulations and geometry to examine the authenticity of one such photo, namely Apollo 17 photo GPN-2000-00113. In addition, a novel approach is employed by creating an experimental scene to illustrate details and provide measurements. The crucial factors on which the geometrical analysis relies are locked in the photograph and are: (a) the apparent position of the Earth relative to the illustrated flag and (b) the point to which the shadow of the astronaut taking the photo reaches, in relation to the flagpole. The analysis and experimental data show geometrical and time mismatches, proving that the photo is a composite.

scholarly journals Isotopic evidence for the formation of the Moon in a canonical giant impact

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sune G. Nielsen ◽  
David V. Bekaert ◽  
Maureen Auro
Keyword(s):  
Solar System ◽  
Isotope Fractionation ◽  
Main Stage ◽  
The Moon ◽  
Giant Impact ◽  
Bulk Silicate Earth ◽  
The Earth ◽  
The Standard Model ◽  
Isotopic Measurements ◽  
Origin Of The Moon

AbstractIsotopic measurements of lunar and terrestrial rocks have revealed that, unlike any other body in the solar system, the Moon is indistinguishable from the Earth for nearly every isotopic system. This observation, however, contradicts predictions by the standard model for the origin of the Moon, the canonical giant impact. Here we show that the vanadium isotopic composition of the Moon is offset from that of the bulk silicate Earth by 0.18 ± 0.04 parts per thousand towards the chondritic value. This offset most likely results from isotope fractionation on proto-Earth during the main stage of terrestrial core formation (pre-giant impact), followed by a canonical giant impact where ~80% of the Moon originates from the impactor of chondritic composition. Our data refute the possibility of post-giant impact equilibration between the Earth and Moon, and implies that the impactor and proto-Earth mainly accreted from a common isotopic reservoir in the inner solar system.

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