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The first generation of long-baseline laser interferometric detectors of gravitational waves will start collecting data in 2001 – 2003. We carefully analyse their planned performance and compare it with the expected strengths of astrophysical sources. The scientific importance of the anticipated discovery of various gravitational wave signals and the reliability of theoretical predictions are taken into account in our analysis. We try to be conservative in evaluating both the theoretical uncertainties in the parameters of the source and the prospects of its detection. Upon considering many possible sources, we place our emphasis on (i) inspiraling binaries consisting of stellar mass black holes and (ii) relic gravitational waves. We conclude that inspiraling binary black holes are likely to be detected by the early ground-based interferometers first. We estimate that the first interferometers will see 2 – 3 events per year from black hole binaries with component masses of 10 – 15M, with a signal-to-noise ratio of about 3, in a network of detectors consisting of GEO, VIRGO and two LIGOs. It appears that other possible sources, including coalescing neutron stars, are unlikely to be detected by the early instruments. We also argue that relic gravitational waves may be discovered by space-based interferometers in the frequency interval 2 × 10⁻³ – 10⁻² Hz, at a signal-to-noise ratio level of about 3.

Based on Raman and hyper-Raman scattering experiments and on direct green light absorption measurements, excitations of a new type — charge transfer excitons — are found to exist in Ge-doped silica fibers, whose self-organization (orientation ordering of dipole moments) leads to positive feedback in response to a static electric field. An electric field of 10⁵ V/cm then results breaking the inversion symmetry of the initially centrally symmetric medium and allowing the second harmonic to be generated. Generation persists only at the medium preparation stage and self-switches off upon a transition to the stationary state.

In the late 1930s and early 1940s, two remarkable physical phenomena — the fission of heavy nuclei and the chain fission reaction — were discovered, implying that a new powerful source of energy (nuclear fission energy) might become a practical possibility for mankind. At that time, however, the political situation in the world made the development of the atomic bomb the main objective of nuclear energy research in the countries involved. The first atomic bombs, notoriously used in the war against Japan, were produced by the United States of America only six and a half years after the discovery of fission. Four years later, the first Soviet atomic bomb was tested. This was a major step toward the establishment of nuclear parity which led to stability and global peace and thus greatly influenced the destiny of human kind. Based on documentary materials covering the period from 1939 to 1949, this paper traces the origin and evolution of the physical ideas behind the first Soviet atomic bomb and discusses the most important events associated with the project.

The key condition for radical progress in technology in the 21th century is the availability of a technique for the controlled production in a solid of 3D patterns incorporating regions of desired physical and chemical properties, with the possibility of downsizing pattern elements to the nanometer scale being a crucial requirement. In this paper, a method for changing the electrical, magnetic, optical and other key physical properties in a direct and deliberate manner by radically modifying the solid's atomic composition is proposed for the first time. The physical foundation of the new nonlithography technology is the observation — thoroughly investigated and well verified in our numerous experiments — that accelerated particle beams can be used to selectively remove atoms from thin films of di- or polyatomic compounds. It is shown, in particular, that by selectively removing atoms of a given sort, dielectrics can be transformed into metals or semiconductors, nonmagnetic materials into magnetic ones, and the optical and other properties of materials can be changed radically. The selective removal of atoms of a specified sort from a material is of great interest for future technologies, especially for those relevant to nanoelectronics and, more broadly, to the numerous 'nanoproblems' ahead in the third millennium.