Lunar laser ranging: 40 years of research

Kokurin, Yu. L.

doi:10.1070/qe2003v033n01abeh002363

Cited by 9 publications

(5 citation statements)

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“…The researchers of the Crimean scientific station of the LPI, in collaboration with French experts, participated in the creation and installation of corner reflectors on both lunar rovers. The accuracy of the measurements, according to the literature was initially 3.0 m. 10,11 It was achieved using a ruby laser with wavelength 694.3 nm, duration of pulse 30 ns and energy 2 J. In subsequent years, automatic control was added and the laser itself was upgraded several times.…”

Section: Short History Of Llr In Craomentioning

confidence: 99%

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The 1970–1984 lunar laser ranging observations in the Crimean Astrophysical Observatory

Tryapitsyn

Pavlov

Yagudina

et al. 2021

Journal for the History of Astronomy

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The Lunar Laser Ranging (LLR) has been the main method of study of the dynamics of the Sun-Earth-Moon system since 1969 to present. Lunar parts of the three modern high-precision ephemerides of the Solar system bodies are based solely on LLR measurements: DE (USA), EPM (Russia), INPOP (France). LLR measurements allow to determine parameters of lunar orbital and rotational motion, as well as some parameters related to terrestrial and lunar tides, and also fundamental relativistic parameters. Those parameters were determined from LLR with high accuracy by different authors. In USSR, LLR measurements were performed in the Crimean Astrophysical Observatory (CrAO) in Nauchny, on the 2.6 m Shajn’s Zenith telescope (ZTSh) with an automated laser ranging system developed by the Russian Lebedev Physical Institute (LPI). Within the time span of 1969–1984, 1400 measurements were obtained. Unlike LLR measurements done in other observatories, they were eventually forgotten and have not made their way into the dataset that is used by scientists worldwide to build lunar ephemerides and conduct other lunar research. The main reason for writing this paper was the discovery by Tryapitsyn, a researcher at the Katziveli station of CrAO, of old printouts containing the 1970–1984 LLR observations made with the ZTSh 2.6 m telescope. Some details were missing from the printouts, which required careful restoration work. In this paper the history of those LLR observations with surrounding historical events is presented, and some details of the analysis these observations are described. Of particular interest is the finding related to the three normal points of Lunokhod-1 ranges obtained in 1974 that allowed Odile Calame to determine the rover’s position with a few kilometers accuracy. Unfortunately, the accuracy was not sufficient for other researchers to confirm and pin down the location of the rover.

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Section: Short History Of Llr In Craomentioning

confidence: 99%

“…Thus, the joint research efforts of the scientific staff of the Crimean Laser Observatory combined with the new evidence found in the old Crimean materials helped to reveal the history of the laser ranging of the Moon in CrAO. 11…”

Section: Llr Observations Obtained In Crao In 1973-1984mentioning

confidence: 99%

The 1970–1984 lunar laser ranging observations in the Crimean Astrophysical Observatory

Tryapitsyn

Pavlov

Yagudina

et al. 2021

Journal for the History of Astronomy

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“…There are nine possible types of principal homogeneous spaces (admitting a group of motions) with a time-dependent metric (the Bianchi classification) in threedimensional space [15]. The introduction of the constraint restricts not only the group of coordinate transformations admissible in GR, but also the group of motions (9) x…”

Section: Evolution Of the Space-time Manifold In The Absence Of Mattermentioning

confidence: 99%

“…Thus, a priori, only the "medium-strong principle" of equivalence is met in this case [8]. However, this cannot be grounds for rejecting the proposed approach as contradicting the experiments verifying the strong equivalence principle for bodies of cosmic scales [9].…”

Section: Introductionmentioning

confidence: 97%

“…The solution of the gravitational equations has enough free parameters to not only ensure the requirement of the equality of the inertial mass of the gravitational field to its gravitational mass, but also to determine inertial mass in accordance with Mach's principle (the latter problem has not been solved in GR). From this point of view, the results of experiments [9] should be considered as an indication that only such (quasi) stationary self-gravitating objects exist for which inertial mass is equal to gravitational mass.…”

Section: Introductionmentioning

confidence: 99%

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Foundations of a Theory of Gravity with a Constraint and Its Canonical Quantization

Sobolev

2021

Found Phys

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The gravitational equations were derived in general relativity (GR) using the assumption of their covariance relative to arbitrary transformations of coordinates. It has been repeatedly expressed an opinion over the past century that such equality of all coordinate systems may not correspond to reality. Nevertheless, no actual verification of the necessity of this assumption has been made to date. The paper proposes a theory of gravity with a constraint, the degenerate variants of which are general relativity (GR) and the unimodular theory of gravity. This constraint is interpreted from a physical point of view as a sufficient condition for the adiabaticity of the process of the evolution of the space–time metric. The original equations of the theory of gravity with the constraint are formulated. On this basis, a unified model of the evolution of the modern, early, and very early Universe is constructed that is consistent with the observational astronomical data but does not require the hypotheses of the existence of dark energy, dark matter or inflatons. It is claimed that: physical time is anisotropic, the gravitational field is the main source of energy of the Universe, the maximum global energy density in the Universe was 64 orders of magnitude smaller the Planckian one, and the entropy density is 18 orders of magnitude higher the value predicted by GR. The value of the relative density of neutrinos at the present time and the maximum temperature of matter in the early Universe are calculated. The wave equation of the gravitational field is formulated, its solution is found, and the nonstationary wave function of the very early Universe is constructed. It is shown that the birth of the Universe was random.

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