Table of contents

Mandelshtam's views on the role of informal physical arguments in deriving the geometric law of refraction are discussed. It is shown that Sivukhin's theorem allows reconciling different approaches to justifying the choice of the refracted wave vector. Wave reflection and refraction are considered for a periodically heterogeneous half-space. It is shown that the analogy between the Snell–Descartes refraction law and the properties of a wave propagating in a chain of discrete interacting elements and in a periodically heterogeneous space is incorrect. The principal role of the homogeneity of interfacing media is stressed. The only case that corresponds to the 'purely' negative refraction is that of a homogeneous refracting medium in which both the dielectric constant and the magnetic permeability are negative.

Two fundamental mechanisms — the Cherenkov effect and anomalous Doppler effect — underlying the emission by an electron during its superluminal motion in medium are considered. Cherenkov emission induced by a single electron and a small electron bunch is spontaneous. In the course of spontaneous Cherenkov emission, the translational motion of an electron is slowed down and the radiation energy grows linearly with time. As the number of radiating electrons increases, Cherenkov emission becomes stimulated. Stimulated Cherenkov emission represents a resonance beam instability. This emission process is accompanied by longitudinal electron bunching in the beam or by the breaking of an electron bunch into smaller bunches, in which case the radiation energy grows exponentially with time. In terms of the longitudinal size L_e of the electron bunch there is a transition region λ < L_e < λδ₀^–1 between the spontaneous and stimulated Cherenkov effects, where λ is the average radiation wavelength, and δ₀ is the dimensionless (in units of the radiation frequency) growth rate of the Cherenkov beam instability. The range to the left of this region is dominated by spontaneous emission, whereas the range to the right of this region is dominated by stimulated emission. In contrast to the Vavilov–Cherenkov effect, the anomalous Doppler effect should always (even for a single electron) be considered as stimulated, because it can only be explained by accounting for the reverse action of the radiation field on the moving electron. During stimulated emission in conditions where anomalous Doppler effect shows itself, an electron is slowed down and spins up; in this case, the radiation energy grows exponentially with time.

Up-to-date data on the fundamental physical constants are briefly reviewed, as are the results of their combined analysis, namely, the new recommended values of the fundamental physical constants [Mohr P J, Taylor B N, Newell D B, "CODATA recommended values of the fundamental physical constants: 2006" Rev. Mod. Phys. 80 633 (2008)]. Following an approach presented previously (Usp. Fiz. Nauk 175 271 (2005) [Phys. Usp. 48 255 (2005)]), the author divides the data into blocks. The same block approach is used to discuss new theoretical and experimental results and their implications for the new recommended values of the constants. A comparison with the previous (1998 and 2002) sets of the recommended values of the constants is given.

This paper presents experimental results on solutocapillary Marangoni convection, an effect that occurs in a thin horizontal layer of the inhomogeneous solution of a surface-tension-active agent (surfactant) either near the free upper boundary of the layer or near the surface of an air bubble injected into the fluid. A procedure using interferometry is developed for simultaneously visualizing convective flow structures and concentration fields. A number of new phenomena are observed, including the deformation and rupture of the liquid layer due to a surfactant droplet spread over its surface; bubble self-motion (migration) toward higher surfactant concentrations; self-sustained convective flow oscillations around stationary bubbles in a fluid vertically stratified in concentration; and the existence of a threshold for a solutal Marangoni flow in thin layers. A comparison of solutocapillary and thermo-capillary phenomena is made.

A review is given of gas-dynamic thermonuclear fusion (GDTF) — a novel line of inertial thermonuclear fusion research based on the cumulative spherical compression of the deuterium–tritium gas using a high explosive charge. Major aspects of the research are examined and the record results achieved by the mid-1980s are discussed.

A scientific outreach session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held on 23 April 2008 at the Institute for High Pressure Physics, RAS, Troitsk, Moscow region. The session was devoted to the 50th anniversary of the Institute. The following reports were presented: (1) Stishov S M (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "The Institute for High Pressure Physics is now 50 (opening address)"; (2) Khvostantsev L G and Slesarev V N (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "Large-volume high-pressure devices for physical investigations"; (3) Popova S V, Brazhkin V V and Dyuzheva T I (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "Structural phase transitions in highly compressed substances and the synthesis of high-pressure phases"; (4) Dzhavadov L N, Gromnitskaya E L, Stepanov G N and Timofeev Yu A (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "Studies of the thermodynamic, elastic, superconducting, and magnetic properties of substances at high pressures"; (5) Dizhur E M, Venttsel V A and Voronovskii A N (Institute for High Pressure Physics, RAS, Troitsk, Moscow region), "Quantum transport at high pressures"; (6) Ryzhov V N, Barabanov A F, Magnitskaya M V and Tareyeva E E (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "Theoretical studies of condensed matter"; (7) Bugakov V I, Antanovich A A, Konyaev Yu S and Slesarev V N (Institute for High Pressure Physics, RAS, Troitsk, Moscow region) "Designing new construction and superhard materials and related tools."

An abridged version of reports 1 –6 is presented below.

• The Institute for High Pressure Physics is now 50 (opening address), Stishov S M Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1055-1059 • Large-volume high-pressure devices for physical investigations, Khvostantsev L G and Slesarev V N Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1059-1063 • Structural phase transitions in highly compressed substances and the synthesis of high-pressure phases, Popova S V, Brazhkin V V and Dyuzheva T I Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1064-1066 • Studies of the thermodynamic, elastic, superconducting, and magnetic properties of substances at high pressures, Dzhavadov L N, Gromnitskaya E L, Stepanov G and Timofeev Yu A Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1066-1070 • Quantum transport at high pressures, Dizhur E M, Venttsel V A and Voronovskii A N Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1070-1077 • Theoretical studies of condensed matter, Ryzhov V N, Barabanov A F, Magnitskaya M V and Tareyeva E E Physics-Uspekhi, 2008, Volume 51, Number 10, Pages 1077-1083