EINSTEIN and MICHELSON The Context of Discovery and the Context of Justification

The philosopher of science is not much intersted in the thought processes which lead to scientific discoveries; he looks for a logical analysis of the completed theory, including the relationships establishing its validity. That is, he is not interested in the context of discovery, but in the context of justification … it appears amazing to what extent the logical analysis of relativity coincides with the original interpretation by its author, as far as it can be constructed from the scanty remarks in EINSTEIN 's publications. In contradistinction to some developments in quantum theory, the logical schema of the theory of relativity corresponds surprisingly with the program which controlled its discovery.     

Phase transitions in perturbed stiff-fluid Friedmann-Robertson-Walker cosmological models

We consider one-soliton perturbations of a flat Friedmann-Robertson-Walker (FRW) cosmological model, with an ideal fluid with pressure equal to the energy density (stiff fluid), in the case where the “pole trajectory” parameter is negative, introducing thereby singularities along certain null hypersurfaces. Starting with a metric that approaches asymptotically the FR W background, we show that it is possible to construct an extension through these hypersurfaces such that the energy momentum tensor T_ab is finite and satisfies the energy conditions. The extension is only C₁, providing a sort of “shock front” with continuity in T_ab, that has an associated phase transition from null dust to stiff fluid, the transition being of the form described by CHANDRASEKHAR and XANTHOPOULOS.     

Method for Validation of the Onboard Attitude Control System Software of the <Emphasis Type="Italic">Auriga</Emphasis> Earth Remote Sensing Small Spacecraft

The paper considers a digital modeling complex for the attitude control system of the Auriga Earth remote sensing small spacecraft. Mathematical models of measuring and executive devices are described. The results of spacecraft orbital attitude tests are presented.     

Technologies of measurements of the sea level

We analyze the contemporary methods and means of measurements of the sea level and inland waters, describe a CTD-meter designed at the Marine Hydrophysical Institute of the Ukrainian National of Science for the determination of the sea level, formulate the requirements to the perfect meter of the water level, and demonstrate that an electronic sounding stick based on the distributed Walsh thermoprofilometers can play the role of a device of this kind.