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The electrokinetically induced vertical component of the electric field in a multilayer fluid-saturated porous medium caused by tidal deformations of the Earth’s crust is calculated. Petrophysical properties change in a jumplike manner at the boundary between two media. The pore pressure gradient at the boundary abruptly reaches a maximum and then exponentially decays, forming a hydrodynamic skin layer. Due to the electrokinetic effect, the electric field behaves in the same way. Observations of the vertical electric field can be used, in principle, to determine the mechanical properties of the medium experiencing deformation. The magnitudes of the effects lie within a range accessible to measurement.

Brief review of principal ideas in respect of the high frequency gravitational radiation generated and detected in the laboratory condition is presented. Interaction of electro-magnetic and gravitational waves into a strong magnetic field is considered as a more promising variant of the laboratory GW-Hertz experiment. The formulae of the direct and inverse Gertsenshtein-Zeldovich effect are derived. Numerical estimates are given and a discussion of a possibility of observation of these effects in a lab is carried out., 10 pages , to be published in Physica Scripta

Methodological aspects are considered for theoretical metrology and the principles for determining basic concepts. The basic concepts in metrology are determined operationally, with the meanings established during the performance of sequences of experimental operations. Differences are pointed out in the definition of the same concepts in metrology and in theoretical physics.

We describe some new estimates concerning the recently proposed SEE (Satellite Energy Exchange) experiment for measuring the gravitational interaction parameters in space. The experiment entails precision tracking of the relative motion of two test bodies (a heavy ''Shepherd'', and a light ''Particle'') on board a drag-free space capsule. The new estimates include (i) the sensitivity of Particle trajectories and G measurement to the Shepherd quadrupole moment uncertainties; (ii) the measurement errors of G and the strength of putative Yukawa-type force whose range parameter λ may be either of the order of a few metres or close to the Earth radius; (iii) a possible effect of the Van Allen radiation belts on the SEE experiment due to test-body electric charging. The main conclusions are that (i) the SEE concept may allow G to be measured with an uncertainty of less tha 1 part in 107 and progress up to two orders of magnitude is possible in the assessment of possible Yukawa forces and (ii) Van Allen charging of test bodies is a significant problem but it may be solved by existing methods.

Project SEE (Satellite Energy Exchange) is an international effort to develop a space-based mission for precise measurements of gravitation. Gravity is the missing link in unification theory. Because of the unique paucity of knowledge about this, the weakest of all known forces, and because gravity must have a key role in any unification theory, many aspects of gravity need to be understood in greater depth. A SEE mission would extend our knowledge of a number of gravitational parameters and effects, which are needed to test unification theories and various modern theories of gravity. SEE is a comprehensive gravitation experiment. A SEE mission would test for violations of the equivalence principle (EP), both by inverse-square-law (ISL) violations and by composition dependence (CD), both at ranges of the order of metres and at ranges on the order of RE. A SEE mission would also determine the gravitational constant G, test for time variation of G, and possibly test for post-Einsteinian orbital resonances. The potential finding of a non-zero time variation of G is perhaps the most important aspect of SEE. A SEE mission will also involve a search for new particles with very low masses, since any evidence of violations of the EP would be analysed in terms of a putative new Yukawa-like particle. Thus, SEE does not merely test for violations of general relativity (GR); SEE is a next-generation gravity mission.

An experimental scheme is proposed for detecting new long-range forces by utilizing a spherical cavity excavated from a sphere and placing a fixed torsion balance within it. It is shown that for the optimal distance between the axes of rotation of the sphere, the cavity, and the torsion balance and for a spatial parameter λ ≈ 10–12 cm, the ultimate attainable sensitivity in the parameter α exceeds the present level by roughly a factor of 105.

Project SEE (Satellite Energy Exchange) is an international effort to organize a new space mission for fundamental measurements in gravitation, including tests of the equivalence principle (EP) by composition dependence (CD) and inverse-square-law (ISL) violations, determination of G, and a test for non-zero G-dot. The CD tests will be both at intermediate distances (a few metres) and at long distances (radius of the Earth, RE). Thus, a SEE mission would obtain accurate information self-consistently on a number of distinct gravitational effects. The EP test by CD at distances of a few metres would provide confirmation of earlier, more precise experiments. All other tests would significantly improve our knowledge of gravity. In particular, the error in G is projected to be less than 1 ppm. Project SEE entails launching a dedicated satellite and making detailed observations of free-floating test bodies within its experimental chamber.

The results are presented of a microgravimetric survey of two bases of the gravimetric station of the All-Union Scientific-Research Institute of Metrology (VNIIM) using an E-54 variometer. The measurements form part of preparations for performing comparisons of absolute ballistic gravimeters at the observatory.

Recently two methods of measuring the gravitational constant G, possible equivalence principle violation (measured by the Eötvös parameter η) and the hypothetic 5th force parameters α and λ on board a drag-free Earth’s satellite were suggested: SEE (Satellite Energy Exchange) and LPH (Libration Point Hitting). These methods are developed and compared. Various particle trajectories near a heavy ball are studied numerically and analytically. Some basic sources of error are analysed. The G measurement procedure is modelled by noise insertion to a “true” trajectory. It is concluded that the presense knowledge of G, α (for λ≥1 m) and η can be improved by at least two orders of magnitude.

Estimates are made of the vertical deformations in the Earth's crust produced by variable loads on regions having characteristic dimensions of the order of thousands of kilometers, which arise from the development and displacement of cyclones and anticyclones and also from the accumulation of snow and the passage of floods on large rivers. It is found that the total deformation in Siberia can attain 30 cm. It is necessary to correct for the periodic displacements in observational points in the service for determining the Earth's rotational parameters. Suggestions are made on organizing experiments on the deformations.

A simulation is described for measuring the newtonian gravitational constant G in the SEE space experiment. Two methods are examined for estimating G: the two-point method and the integral one. When the two-point method is used, to provide an error not more than ΔG/G ≈ 1·10−6 requires path measurements to be performed with an error of not more than 1·10−8 m=λ/50 (λ is the green line wavelength). In the integral method, the same error in estimating G is attained with an error of measurement different by two orders of magnitude, 1·10−6 m.

Errors affecting the assessment of the attainable accuracy of measurement of Newton's gravitational constant in an experiment performed to observe the relative motion of two bodies housed in a drift-free artificial earth satellite are investigated with a view toward finding a realistic theoretical model.

The conditions are described for carrying out an experiment that should permit the accuracy of determination of the gravitational constant to be increased by an order of magnitude.

The results of numerical modeling of the trajectories of motion of a light body (a “particle”) with respect to a heavier body in the orbit of an artificial satellite are presented [1]. Plane circular and elliptic orbits of the heavy body are considered, ignoring the nonsphericity of the gravitational field of the earth, and also plane circular equatorial orbits taking the quadrupole moment of the earth into account. The sensitivity of the trajectories to small variations of the initial conditions and values of the parameters of the gravitational interaction is investigated. It is shown that for the space experiment carried out in [2] to be successful for determining the gravitational constant G and the parameters of the five-force, and to check the principle of equivalence at large distances, the theoretical model of the motion of a “particle/rd must take into account all the perturbations which lead to a displacement of the trajectories of more than 10−4 mm.

An analysis is presented of a space experiment whose purpose is to enhance the accuracy of measurement of the gravitational constant G, improve the estimates of the fifth force parameters α and λ,and finally to verify the equivalence principle. The experiment involves exact measurements of the trajectories of a light body relative to a heavy body on a drag-free Earth satellite. Estimations of the possible effect of various factors on the relative motion trajectory are made. The equations of relative motion are derived for various types of satellite orbits. Some preliminary estimates of the accuracy of the measurements are presented which show that the experiment proposed seems to hold promise.

According to the controversial results of recent experiments for fifth force, we present a classification of all possible types of theories leading to non-Newtonian forces. The theoretical analysis shows that if the interaction potential differs from the Newton's law the interactions of macro- and micro-bodies are in general distinguishable. The calculation also shows that Long's result can be improved by several orders if the new method proposed is used.

A significant correlation was established between the measured vertical displacements of the Mendeleevo GPS Station and the calculated deflections of the Earth's surface caused by changes of atmospheric pressure on the Eurasian continent. A correlation was also established with the local atmospheric pressure at the Mendeleevo station.

There are theoretical grounds and some experimental basis for assuming that Newton's law of attraction is violated at short distances (see, e.g., [i]). This can be attributed to dependence of the gravitational constant on distance or appearance of still another, fifth interaction in addition to the four known ones (strong, weak, electromagnetic, and gravitational). All experiments to detect fifth interaction forces are carried out against a background of Newtonian forces, which hampers interpretation of their results.

lomb) and the units of magnetic- and electric-field strength and electric and magnetic induction and thus becomes a part of the system of electromagnetic units. In an ampere balance, the electromagnetic force of the interacting currents, which is proportional to the square of the current I flowing through the electromagnetic system, is balanced by a weight on the other pan of the balance: i/c 2 I2f = mg. Here, f is a dimensionless function of the geometric parameters of the system, c is the velocity of light, m is the mass of the weight, and g is the free-fall acceleration. Finally, the scale of the ampere unit is determined by a combination of fundamental physical constants - the gravitational constant G and the velocity of light c: I = cr - and by two standard units (mass and length) and a dimensionless function. The dependence of the dimensions of units of physical quantities on the fundamental constants is not single-valued; it is determined by the operative system of physical units. Recently (in 1983), the unit of length (the meter) was redefined as the distance traversed by light in some portion of a second: ~s = cat. The second is defined as the frequency of hyperfine splitting of a cesium atom. As a result, as is readily apparent, the velocity of light disappears from the units of the electromagnetic quantities (ampere, coulomb, tesla, etc.): I = ms ~s f~- The gravitational constant, however, re~ains in the system of electromagnetic units. Obviously, quantum units of the volt~ ohm, and ampere will be used in the near future, but this gives rise to a new problem ~which is automatically solved in the present definition of the ampere) - the problem of consistency of the systems of electromagnetic and mechanical quantities. It is possible that the ampere balance (or a variation of it) will continue to be used for this purpose for a considerable period of time. Explicitly or implicitly, the gravitational constant is a part of a number of standards of mechanical units: pressure, acoustic pressure, etc.

The behavior of two bodies interacting gravitationally onboard a drift-free Earth satellite orbiting at the altitudes of the Alpha international space station is investigated. A numerical simulation of the trajectories of the relative motion of aparticle is performed, as a result of which preliminary estimates of the precision of the experiment are obtained. An estimate of the measurement precision of the parameters of gravitational interaction is given.