Table of contents

Currently available models of one of the most intriguing types of unsteady rf solar emission, millisecond solar radio spikes, are discussed. A comparative analysis of the models' implications and of the body of existing data yields an outline of the most realistic radio spike model possible. The spikes are produced by the cyclotron maser mechanism. The cyclotron cone instability is caused by fast electrons distributed over energies according to a (piecewise) power law. The angular part of the distribution function (whose exact form is, as yet, undetermined) suffers fluctuations due to the magnetic field inhomogeneities that arise in the burst loop as a consequence of the original energy release. In some portions of the loop the distribution is not anisotropic enough to secure the development of a cyclotron instability; it is in these 'microtraps' where individual spikes form. Key areas of future theoretical and experimental research are suggested with a view to verifying the adequacy and realizing the diagnostic potential of the model.

A procedure for calculating antiferromagnetic resonance (AFMR) frequencies is discussed in which a new form of the magnetohydrodynamic equations is employed. As an example, orthorhombic antiferromagnets with an orthoferrite-type magnetic exchange structure are considered. The application to antiferromagnets with other crystallographic and magnetic structures is discussed.

In amplifying media steady-state waves can travel faster than the speed of light in vacuum without violating the principles of special relativity. The possibility of generating superluminal waves in induced elementary particle production processes is discussed.

On introduction of gravitational acceleration into the calculation of length and velocity scales, a set of dimensionless parameters appears in the mathematical model which enable the behaviour of convection and heat and mass transfer under changing gravitational conditions to be predicted. By directly simulating the equations of motion and heat transfer, the effectiveness of the proposed formulation of conservation laws in treating such phenomena in liquids is demonstrated for both isothermal and non-isothermal cases and under both terrestrial and space conditions.

Some methodological aspects of the thermodynamics of dielectrics are discussed. In particular, it is noted that in the general case neither the electric displacement D nor the electric field strength E can be taken as the thermodynamic parameter defining the state of a polarized medium and that the electric polarization P is the appropriate choice. The relation between D and E as defined by the material equation of a medium is shown to be valid only in the state of thermodynamic equilibrium and hence is violated by fluctuations of P. In such an event, the material equation of a dielectric is not an analogue of the equation of state of the substance, which relates the pressure to the volume.

The discovery of the combination scattering of light (the Raman effect) is discussed briefly in historical perspective. Landsberg and Mandel'shtam in Moscow observed spectral lines of the new phenomenon for the first time in crystals on February 21, 1928, and published their results on July 13, 1928, while Raman and Krishnan, in Calcutta, observed similar lines in a number of liquids on February 28, 1928, and published their results on April 21, 1928. Landsberg and Mandel'shtam gave the right interpretation of the new phenomenon in their first publication. The reason for the delay of this publication is explained. A brief note is given on the fate of the discovery and of the people who made it. Raman is the only one who was awarded the Nobel Prize for physics in 1930. The list of the 1930 Nobel Prize nominees in physics is presented. Developments in the field of combination scattering are discussed and the role of the phenomenon in applied research and science illustrated.